Magnetic head for perpendicular magnetic recording

ABSTRACT

A magnetic layer for writing incorporates: a pole layer having an end face located in a medium facing surface; and an upper yoke layer. A first magnetic layer for flux concentration is connected to the pole layer at a location away from the medium facing surface, and passes a magnetic flux corresponding to a magnetic field generated by a first coil. A second magnetic layer for flux concentration is connected to the upper yoke layer at a location away from the medium facing surface, and passes a magnetic flux corresponding to a magnetic field generated by a second coil. A nonmagnetic layer is disposed between the pole layer and the upper yoke layer. The upper yoke layer is connected to the pole layer at a location closer to the medium facing surface than the nonmagnetic layer.

This is a Division of application Ser. No. 11/546,902 filed Oct. 13,2006. The disclosure of the prior applications is hereby incorporated byreference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnetic head for perpendicularmagnetic recording that is used for writing data on a recording mediumby means of a perpendicular magnetic recording system.

2. Description of the Related Art

The recording systems of magnetic read/write devices include alongitudinal magnetic recording system wherein signals are magnetized inthe direction along the surface of the recording medium (thelongitudinal direction) and a perpendicular magnetic recording systemwherein signals are magnetized in the direction orthogonal to thesurface of the recording medium. It is known that the perpendicularmagnetic recording system is harder to be affected by thermalfluctuation of the recording medium and capable of implementing higherlinear recording density, compared with the longitudinal magneticrecording system.

Like magnetic heads for longitudinal magnetic recording, magnetic headsfor perpendicular magnetic recording typically used have a structure inwhich a reproducing (read) head having a magnetoresistive element (thatmay be hereinafter called an MR element) for reading and a recording(write) head having an induction-type electromagnetic transducer forwriting are stacked on a substrate. The write head comprises a magneticpole layer that produces a magnetic field in the direction orthogonal tothe surface of the recording medium.

For the perpendicular magnetic recording system, it is an improvement inrecording medium and an improvement in write head that mainlycontributes to an improvement in recording density. It is a reduction intrack width and an improvement in write characteristics that isparticularly required for the write head to achieve higher recordingdensity. On the other hand, if the track width is reduced, the writecharacteristics, such as an overwrite property that is a parameterindicating an overwriting capability, suffers degradation. It istherefore required to achieve better write characteristics as the trackwidth is reduced.

A magnetic head used for a magnetic disk drive such as a hard disk driveis typically provided in a slider. The slider has a medium facingsurface that faces toward a recording medium. The medium facing surfacehas an air-inflow-side end and an air-outflow-side end. The sliderslightly flies over the surface of the recording medium by means of theairflow that comes from the air-inflow-side end into the space betweenthe medium facing surface and the recording medium. The magnetic head istypically disposed near the air-outflow-side end of the medium facingsurface of the slider. In a magnetic disk drive the magnetic head isaligned through the use of a rotary actuator, for example. In this case,the magnetic head moves over the recording medium along a circular orbitcentered on the center of rotation of the rotary actuator. In such amagnetic disk drive, a tilt of the magnetic head with respect to thetangent of the circular track, which is called a skew, occurs accordingto the position of the magnetic head across the tracks.

In a magnetic disk drive of the perpendicular magnetic recording systemthat exhibits a better capability of writing on a recording medium thanthe longitudinal magnetic recording system, in particular, if theabove-mentioned skew occurs, problems arise, such as an occurrence of aphenomenon in which data stored on an adjacent track is erased when datais written on a specific track (that is hereinafter called adjacenttrack erase), or unwanted writing between adjacent two tracks. Toachieve higher recording density, it is required to suppress adjacenttrack erase. Unwanted writing between adjacent two tracks affectsdetection of servo signals for alignment of the magnetic head and thesignal-to-noise ratio of a read signal.

A technique is known for preventing the above-described problemsresulting from the skew, as disclosed in U.S. Pat. No. 6,504,675 B1, forexample. According to this technique, an end face of the pole layerlocated in the medium facing surface is made to have a shape in whichone of the sides of the end face located backward along the direction oftravel of the recording medium (that is, the side located closer to theair inflow end of the slider) is shorter than the opposite side.

As a magnetic head for perpendicular magnetic recording, a magnetic headcomprising the pole layer and a shield is known, as disclosed in U.S.Pat. No. 4,656,546, for example. In the medium facing surface of thismagnetic head, an end face of the shield is located forward of the endface of the pole layer along the direction of travel of the recordingmedium with a specific small space therebetween. Such a magnetic headwill be hereinafter called a shield-type head. In the shield-type headthe shield prevents a magnetic flux from reaching the recording medium,the flux being generated from the end face of the pole layer andextending in directions except the direction orthogonal to the surfaceof the recording medium. In addition, the shield has a function ofreturning a magnetic flux that has been generated from the end face ofthe pole layer and has magnetized the recording medium. The shield-typehead achieves a further improvement in linear recording density.

U.S. Pat. No. 4,672,493 discloses a magnetic head having such astructure that magnetic layers are respectively provided forward andbackward of a middle magnetic layer to be a pole layer along thedirection of travel of a recording medium and that coils arerespectively provided between the middle magnetic layer and the magneticlayer located forward and between the middle magnetic layer and themagnetic layer located backward. According to this magnetic head, it ispossible to increase components in the direction orthogonal to thesurface of the recording medium among components of the magnetic fieldgenerated from an end of the middle magnetic layer closer to the mediumfacing surface.

U.S. Pat. No. 6,954,340 B2 discloses a magnetic head having such astructure that return poles are respectively provided forward andbackward of a main pole to be a pole layer along the direction of travelof a recording medium and that coils are respectively provided betweenthe main pole and the return pole located forward and between the mainpole and the return pole located backward. This magnetic head has twoside shields that connect the two return poles to each other and thatare disposed on both sides of the main pole opposed to each other in thedirection of track width.

Reference is now made to FIG. 37 to describe a basic configuration ofthe shield-type head. FIG. 37 is a cross-sectional view of the main partof an example of the shield-type head. This shield-type head comprises:a medium facing surface 100 that faces toward a recording medium; a coil101 for generating a magnetic field corresponding to data to be writtenon the medium; a pole layer 102 having an end located in the mediumfacing surface 100, allowing a magnetic flux corresponding to the fieldgenerated by the coil 101 to pass, and generating a write magnetic fieldfor writing the data on the medium by means of the perpendicularmagnetic recording system; a shield layer 103 having an end located inthe medium facing surface 100 and having a portion located away from themedium facing surface 100 and coupled to the pole layer 102; a gap layer104 provided between the pole layer 102 and the shield layer 103; and aninsulating layer 105 covering the coil 101. An insulating layer 106 isdisposed around the pole layer 102. The shield layer 103 is covered witha protection layer 107.

In the medium facing surface 100, the end of the shield layer 103 islocated forward of the end of the pole layer 102 along the direction Tof travel of the recording medium with a specific space created by thethickness of the gap layer 104. At least part of the coil 101 isdisposed between the pole layer 102 and the shield layer 103 andinsulated from the pole layer 102 and the shield layer 103.

The coil 101 is made of a conductive material such as copper. The polelayer 102 and the shield layer 103 are made of a magnetic material. Thegap layer 104 is made of an insulating material such as alumina (Al₂O₃).The insulating layer 105 is made of photoresist, for example.

In the head of FIG. 37 the gap layer 104 is disposed on the pole layer102 and the coil 101 is disposed on the gap layer 104. The coil 101 iscovered with the insulating layer 105. One of the ends of the insulatinglayer 105 closer to the medium facing surface 100 is located at adistance from the medium facing surface 100. In the region from themedium facing surface 100 to the end of the insulating layer 105 closerto the medium facing surface 100, the shield layer 103 faces toward thepole layer 102 with the gap layer 104 disposed in between. Throat heightTH is the length (height) of the portions of the pole layer 102 and theshield layer 103 facing toward each other with the gap layer 104disposed in between, the length being taken from the end closer to themedium facing surface 100 to the other end. The throat height THinfluences the intensity and distribution of the field generated fromthe pole layer 102 in the medium facing surface 100.

The location of the end of a bit pattern to be written on a recordingmedium by the head of FIG. 37 is determined by the location of an end ofthe end face of the pole layer 102 located in the medium facing surface100, the end being located forward along the direction T of travel ofthe recording medium. At a location forward of the end face of the polelayer 102 along the direction T of travel of the recording medium, theshield layer 103 takes in a magnetic flux generated from the end face ofthe pole layer 102 and extending in directions except the directionorthogonal to the surface of the recording medium. The shield layer 103thereby prevents this flux from reaching the recording medium. As aresult, it is possible to prevent a direction of magnetization of thebit pattern already written on the medium from being changed due to theeffect of the above-mentioned flux.

In the shield-type head as shown in FIG. 37, for example, it ispreferred to reduce the throat height TH to improve the overwriteproperty. It is required that the throat height TH be 0.1 to 0.3micrometer (μm), for example. When such a small throat height TH isrequired, the following problems arise in the head of FIG. 37.

That is, when the head of FIG. 37 is in operation, the insulating layer105 may expand due to the heat generated by the coil 101, and an endportion of the shield layer 103 closer to the medium facing surface 100may thereby protrude. Particularly when the throat height TH is small, aportion of the shield layer 103 located between the insulating layer 105and the medium facing surface 100 is thin, so that the end portion ofthe shield layer 103 closer to the medium facing surface 100 is morelikely to protrude. The protrusion of the end portion of the shieldlayer 103 during operation of the head makes a collision of the sliderwith the recording medium occur more frequently.

According to the magnetic head comprising two coils disposed to sandwichthe pole layer, as disclosed in U.S. Pat. No. 4,672,493 and U.S. Pat.No. 6,954,340 B2, it is possible to make the heat value of each of thetwo coils smaller than that of a coil of a magnetic head in which thecoil is the only one coil provided.

However, the magnetic heads disclosed in U.S. Pat. No. 4,672,493 andU.S. Pat. No. 6,954,340 B2 have problems as will now be described.First, in the magnetic head disclosed in U.S. Pat. No. 4,672,493, at alocation away from the medium facing surface, the magnetic layer locatedforward is connected to the top surface of the middle magnetic layer,and the magnetic layer located backward is connected to the bottomsurface of the middle magnetic layer. In addition, the interface betweenthe middle magnetic layer and the magnetic layer located forward and theinterface between the middle magnetic layer and the magnetic layerlocated backward are opposed to each other. Therefore, in this magnetichead, in a region between these two interfaces, the flow of a magneticflux that has come into the middle magnetic layer from the magneticlayer located forward and the flow of a magnetic flux that has come intothe middle magnetic layer from the magnetic layer located backward arenearly opposite in direction. As a result, in the middle magnetic layerof this magnetic head, there occurs repulsion between the magnetic fluxthat has come into the middle magnetic layer from the magnetic layerlocated forward and the magnetic flux that has come into the middlemagnetic layer from the magnetic layer located backward, and the fluxdensity of the middle magnetic layer may be thereby reduced, which mayresult in degradation of overwrite property.

In the magnetic head disclosed in U.S. Pat. No. 6,954,340 B2, at alocation away from the medium facing surface, the return pole locatedforward is connected to the top surface of the main pole with a firstmagnetic stud disposed in between, and the return pole located backwardis connected to the bottom surface of the main pole with a secondmagnetic stud disposed in between. In addition, the interface betweenthe main pole and the first magnetic stud and the interface between themain pole and the second magnetic stud are opposed to each other.Therefore, in this magnetic head, in a region between these twointerfaces, the flow of a magnetic flux that has come into the main polefrom the return pole located forward via the first magnetic stud and theflow of a magnetic flux that has come into the main pole from the returnpole located backward via the second magnetic stud are nearly oppositein direction. As a result, in the main pole of this magnetic head, thereoccurs repulsion between the magnetic flux that has come into the mainpole from the return pole located forward via the first magnetic studand the magnetic flux that has come into the main pole from the returnpole located backward via the second magnetic stud, and the flux densityof the main pole may be thereby reduced, which may result in degradationof overwrite property.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to provide a magnetic head forperpendicular magnetic recording comprising a magnetic layer generatinga write magnetic field and two coils located to sandwich the magneticlayer, the head being capable of preventing a reduction in flux densityof the magnetic layer.

A first magnetic head for perpendicular magnetic recording of theinvention comprises: a medium facing surface that faces toward arecording medium; a first coil and a second coil each generating amagnetic field corresponding to data to be written on the recordingmedium; a magnetic layer for writing having an end face located in themedium facing surface, allowing a magnetic flux corresponding to thefield generated by each of the first and second coils to passtherethrough, and generating a write magnetic field for writing the dataon the recording medium by means of a perpendicular magnetic recordingsystem; a first magnetic layer for flux concentration disposed backwardof the magnetic layer for writing along a direction of travel of therecording medium, connected to the magnetic layer for writing at alocation away from the medium facing surface, and allowing a magneticflux corresponding to the field generated by the first coil to pass; anda second magnetic layer for flux concentration disposed forward of themagnetic layer for writing along the direction of travel of therecording medium, connected to the magnetic layer for writing at alocation away from the medium facing surface, and allowing a magneticflux corresponding to the field generated by the second coil to pass.

When seen in a direction orthogonal to the interface between the firstmagnetic layer for flux concentration and the magnetic layer forwriting, the first coil is wound around the interface between the firstmagnetic layer for flux concentration and the magnetic layer forwriting. When seen in a direction orthogonal to the interface betweenthe second magnetic layer for flux concentration and the magnetic layerfor writing, the second coil is wound around the interface between thesecond magnetic layer for flux concentration and the magnetic layer forwriting. When seen in a direction orthogonal to the interface betweenthe second magnetic layer for flux concentration and the magnetic layerfor writing, the interface between the second magnetic layer for fluxconcentration and the magnetic layer for writing is disposed at alocation that does not coincide with the interface between the firstmagnetic layer for flux concentration and the magnetic layer forwriting. Such a configuration suppresses repulsion between a magneticflux flowing into the magnetic layer for writing from the first magneticlayer for flux concentration and a magnetic flux flowing into themagnetic layer for writing from the second magnetic layer for fluxconcentration.

In the first magnetic head of the invention, the magnetic layer forwriting may incorporate: a pole layer having the end face located in themedium facing surface; and a yoke layer connected to the pole layer anddisposed forward of the pole layer along the direction of travel of therecording medium at a location away from the medium facing surface. Inthis case, the first magnetic layer for flux concentration is connectedto the pole layer while the second magnetic layer for flux concentrationis connected to the yoke layer.

In the first magnetic head of the invention, the magnetic layer forwriting may incorporate: a pole layer having the end face located in themedium facing surface; and a yoke layer connected to the pole layer anddisposed backward of the pole layer along the direction of travel of therecording medium at a location away from the medium facing surface. Inthis case, the first magnetic layer for flux concentration is connectedto the yoke layer while the second magnetic layer for flux concentrationis connected to the pole layer.

In the first magnetic head of the invention, the second magnetic layerfor flux concentration may have an end face located in the medium facingsurface, and part of the second coil may be disposed between the secondmagnetic layer for flux concentration and the magnetic layer forwriting.

In the first magnetic head of the invention, the first magnetic layerfor flux concentration may have a portion located to sandwich part ofthe first coil between the magnetic layer for writing and itself.

The first magnetic head of the invention may further comprise: a shieldlayer disposed forward of the magnetic layer for writing along thedirection of travel of the recording medium and having an end facelocated in the medium facing surface; and a gap layer made of anonmagnetic material and disposed between the magnetic layer for writingand the shield layer. In this case, in the medium facing surface, theend face of the shield layer is located forward of the end face of themagnetic layer for writing along the direction of travel of therecording medium with a specific space created by the thickness of thegap layer. In addition, the end face of the magnetic layer for writinghas a side located adjacent to the gap layer, the side defining thetrack width. In this case, the first magnetic layer for fluxconcentration may incorporate a portion located to sandwich part of thefirst coil between the magnetic layer for writing and itself, and themagnetic head may further comprise a coupling portion coupling theshield layer and the first magnetic layer for flux concentration to eachother without touching the magnetic layer for writing.

A second or third magnetic head for perpendicular magnetic recording ofthe invention comprises: a medium facing surface that faces toward arecording medium; a first coil and a second coil each generating amagnetic field corresponding to data to be written on the recordingmedium; a magnetic layer for writing having an end face located in themedium facing surface, allowing a magnetic flux corresponding to thefield generated by each of the first and second coils to passtherethrough, and generating a write magnetic field for writing the dataon the recording medium by means of a perpendicular magnetic recordingsystem; a first magnetic layer for flux concentration disposed backwardof the magnetic layer for writing along a direction of travel of therecording medium, connected to the magnetic layer for writing at alocation away from the medium facing surface, and allowing a magneticflux corresponding to the field generated by the first coil to pass; anda second magnetic layer for flux concentration disposed forward of themagnetic layer for writing along the direction of travel of therecording medium, connected to the magnetic layer for writing at alocation away from the medium facing surface, and allowing a magneticflux corresponding to the field generated by the second coil to pass.

In the second magnetic head of the invention, the magnetic layer forwriting incorporates: a pole layer having the end face located in themedium facing surface; and a yoke layer connected to the pole layer anddisposed forward of the pole layer along the direction of travel of therecording medium at a location away from the medium facing surface. Thefirst magnetic layer for flux concentration is connected to the polelayer. The second magnetic layer for flux concentration is connected tothe yoke layer. When seen in a direction orthogonal to the interfacebetween the first magnetic layer for flux concentration and the polelayer, the first coil is wound around the interface between the firstmagnetic layer for flux concentration and the pole layer. When seen in adirection orthogonal to the interface between the second magnetic layerfor flux concentration and the yoke layer, the second coil is woundaround the interface between the second magnetic layer for fluxconcentration and the yoke layer.

The second magnetic head of the invention further comprises anonmagnetic layer made of a nonmagnetic material and disposed betweenthe pole layer and the yoke layer. When seen in a direction orthogonalto the interface between the second magnetic layer for fluxconcentration and the yoke layer, at least part of the nonmagnetic layeris disposed at a location that coincides with at least part of thisinterface. The yoke layer is connected to the pole layer at least at alocation closer to the medium facing surface than the nonmagnetic layer.Such a configuration suppresses repulsion between a magnetic fluxflowing into the pole layer from the first magnetic layer for fluxconcentration and a magnetic flux flowing into the yoke layer from thesecond magnetic layer for flux concentration.

In the second magnetic head of the invention, the second magnetic layerfor flux concentration may have an end face located in the medium facingsurface, and part of the second coil may be disposed between the secondmagnetic layer for flux concentration and the magnetic layer forwriting.

In the second magnetic head of the invention, the first magnetic layerfor flux concentration may have a portion located to sandwich part ofthe first coil between the magnetic layer for writing and itself.

The second magnetic head of the invention may further comprise: a shieldlayer disposed forward of the pole layer along the direction of travelof the recording medium and having an end face located in the mediumfacing surface; and a gap layer made of a nonmagnetic material anddisposed between the pole layer and the shield layer. In this case, inthe medium facing surface, the end face of the shield layer is locatedforward of the end face of the pole layer along the direction of travelof the recording medium with a specific space created by the thicknessof the gap layer. The end face of the pole layer has a side locatedadjacent to the gap layer, the side defining the track width. In thiscase, the first magnetic layer for flux concentration may incorporate aportion located to sandwich part of the first coil between the magneticlayer for writing and itself, and the magnetic head may further comprisea coupling portion coupling the shield layer and the first magneticlayer for flux concentration to each other without touching the magneticlayer for writing.

In the third magnetic head of the invention, the magnetic layer forwriting incorporates: a pole layer having the end face located in themedium facing surface; and a yoke layer connected to the pole layer anddisposed backward of the pole layer along the direction of travel of therecording medium at a location away from the medium facing surface. Thefirst magnetic layer for flux concentration is connected to the yokelayer. The second magnetic layer for flux concentration is connected tothe pole layer. When seen in a direction orthogonal to the interfacebetween the first magnetic layer for flux concentration and the yokelayer, the first coil is wound around the interface between the firstmagnetic layer for flux concentration and the yoke layer. When seen in adirection orthogonal to the interface between the second magnetic layerfor flux concentration and the pole layer, the second coil is woundaround the interface between the second magnetic layer for fluxconcentration and the pole layer.

The third magnetic head of the invention further comprises a nonmagneticlayer made of a nonmagnetic material and disposed between the pole layerand the yoke layer. When seen in a direction orthogonal to the interfacebetween the first magnetic layer for flux concentration and the yokelayer, at least part of the nonmagnetic layer is disposed at a locationthat coincides with at least part of this interface. The yoke layer isconnected to the pole layer at least at a location closer to the mediumfacing surface than the nonmagnetic layer. Such a configurationsuppresses repulsion between a magnetic flux flowing into the yoke layerfrom the first magnetic layer for flux concentration and a magnetic fluxflowing into the pole layer from the second magnetic layer for fluxconcentration.

In the third magnetic head of the invention, the second magnetic layerfor flux concentration may have an end face located in the medium facingsurface, and part of the second coil may be disposed between the secondmagnetic layer and the magnetic layer for writing.

In the third magnetic head of the invention, the first magnetic layerfor flux concentration may have a portion located to sandwich part ofthe first coil between the magnetic layer for writing and itself.

The third magnetic head of the invention may further comprise: a shieldlayer disposed forward of the pole layer along the direction of travelof the recording medium and having an end face located in the mediumfacing surface; and a gap layer made of a nonmagnetic material anddisposed between the pole layer and the shield layer. In this case, inthe medium facing surface, the end face of the shield layer is locatedforward of the end face of the pole layer along the direction of travelof the recording medium with a specific space created by the thicknessof the gap layer. The end face of the pole layer has a side locatedadjacent to the gap layer, the side defining the track width. In thiscase, the first magnetic layer for flux concentration may incorporate aportion located to sandwich part of the first coil between the magneticlayer for writing and itself, and the magnetic head may further comprisea coupling portion coupling the shield layer and the first magneticlayer for flux concentration to each other without touching the magneticlayer for writing.

According to the first magnetic head of the invention, the interfacebetween the second magnetic layer for flux concentration and themagnetic layer for writing is disposed at a location that does notcoincide with the interface between the first magnetic layer for fluxconcentration and the magnetic layer for writing. As a result, accordingto the invention, it is possible to suppress repulsion between themagnetic flux flowing into the magnetic layer for writing from the firstmagnetic layer for flux concentration and the magnetic flux flowing intothe magnetic layer for writing from the second magnetic layer for fluxconcentration. According to the invention, it is thereby possible toprevent a reduction in flux density of the magnetic layer for writing.

The second magnetic head of the invention comprises the nonmagneticlayer disposed between the pole layer and the yoke layer, and, when seenin a direction orthogonal to the interface between the second magneticlayer for flux concentration and the yoke layer, at least part of thenonmagnetic layer is disposed at a location that coincides with at leastpart of this interface. The yoke layer is connected to the pole layer atleast at a location closer to the medium facing surface than thenonmagnetic layer. As a result, according to the invention, it ispossible to suppress repulsion between the magnetic flux flowing intothe pole layer from the first magnetic layer for flux concentration andthe magnetic flux flowing into the yoke layer from the second magneticlayer for flux concentration. According to the invention, it is therebypossible to prevent a reduction in flux density of the magnetic layerfor writing.

The third magnetic head of the invention comprises the nonmagnetic layerdisposed between the pole layer and the yoke layer, and, when seen in adirection orthogonal to the interface between the first magnetic layerfor flux concentration and the yoke layer, at least part of thenonmagnetic layer is disposed at a location that coincides with at leastpart of this interface. The yoke layer is connected to the pole layer atleast at a location closer to the medium facing surface than thenonmagnetic layer. As a result, according to the invention, it ispossible to suppress repulsion between the magnetic flux flowing intothe yoke layer from the first magnetic layer for flux concentration andthe magnetic flux flowing into the pole layer from the second magneticlayer for flux concentration. According to the invention, it is therebypossible to prevent a reduction in flux density of the magnetic layerfor writing.

Other and further objects, features and advantages of the invention willappear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view for illustrating the configuration of amagnetic head of a first embodiment of the invention.

FIG. 2 is a front view of the medium facing surface of the magnetic headof the first embodiment of the invention.

FIG. 3 is a top view of a pole layer of the magnetic head of the firstembodiment of the invention.

FIG. 4A and FIG. 4B are views for illustrating a step of a method ofmanufacturing the magnetic head of the first embodiment of theinvention.

FIG. 5A and FIG. 5B are views for illustrating a step that follows thestep shown in FIG. 4A and FIG. 4B.

FIG. 6A and FIG. 6B are views for illustrating a step that follows thestep shown in FIG. 5A and FIG. 5B.

FIG. 7A and FIG. 7B are views for illustrating a step that follows thestep shown in FIG. 6A and FIG. 6B.

FIG. 8A and FIG. 8B are views for illustrating a step that follows thestep shown in FIG. 7A and FIG. 7B.

FIG. 9A and FIG. 9B are views for illustrating a step that follows thestep shown in FIG. 8A and FIG. 8B.

FIG. 10A and FIG. 10B are views for illustrating a step that follows thestep shown in FIG. 9A and FIG. 9B.

FIG. 11 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the first embodiment of theinvention.

FIG. 12 is a cross-sectional view for illustrating the configuration ofa magnetic head of a second embodiment of the invention.

FIG. 13 is a cross-sectional view for illustrating an example ofconfiguration of a magnetic head of a third embodiment of the invention.

FIG. 14 is a cross-sectional view for illustrating another example ofconfiguration of the magnetic head of the third embodiment of theinvention.

FIG. 15 is a cross-sectional view for illustrating still another exampleof configuration of the magnetic head of the third embodiment of theinvention.

FIG. 16 is a cross-sectional view for illustrating the configuration ofa magnetic head of a fourth embodiment of the invention.

FIG. 17 is a cross-sectional view for illustrating the configuration ofa magnetic head of a fifth embodiment of the invention.

FIG. 18 is a cross-sectional view for illustrating the configuration ofa magnetic head of a sixth embodiment of the invention.

FIG. 19 is a cross-sectional view for illustrating the configuration ofa magnetic head of a seventh embodiment of the invention.

FIG. 20 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the seventh embodiment of theinvention.

FIG. 21 is a cross-sectional view for illustrating the configuration ofa magnetic head of a modification example of the seventh embodiment ofthe invention.

FIG. 22 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the modification example shownin FIG. 21.

FIG. 23 is a cross-sectional view for illustrating the configuration ofa magnetic head of an eighth embodiment of the invention.

FIG. 24 is a front view of the medium facing surface of the magnetichead of the eighth embodiment of the invention.

FIG. 25 is a cross-sectional view taken along line 25-25 of FIG. 23.

FIG. 26 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the eighth embodiment of theinvention.

FIG. 27 is a cross-sectional view for illustrating the configuration ofa magnetic head of a modification example of the eighth embodiment ofthe invention.

FIG. 28 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the modification example shownin FIG. 27.

FIG. 29 is a cross-sectional view for illustrating the configuration ofa magnetic head of a ninth embodiment of the invention.

FIG. 30 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the ninth embodiment of theinvention.

FIG. 31 is a cross-sectional view for illustrating the configuration ofa magnetic head of a tenth embodiment of the invention.

FIG. 32 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the tenth embodiment of theinvention.

FIG. 33 is a cross-sectional view for illustrating the configuration ofa magnetic head of an eleventh embodiment of the invention.

FIG. 34 is a cross-sectional view for illustrating the configuration ofa magnetic head of a twelfth embodiment of the invention.

FIG. 35 is a cross-sectional view for illustrating the configuration ofa magnetic head of a thirteenth embodiment of the invention.

FIG. 36 is a cross-sectional view for illustrating the configuration ofa magnetic head of a fourteenth embodiment of the invention.

FIG. 37 is a cross-sectional view illustrating a main part of an exampleof a shield-type head.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

Preferred embodiments of the invention will now be described in detailwith reference to the accompanying drawings. Reference is now made toFIG. 1 to FIG. 3 to describe the configuration of a magnetic head forperpendicular magnetic recording of a first embodiment of the invention.FIG. 1 is a cross-sectional view for illustrating the configuration ofthe magnetic head of the embodiment. FIG. 1 illustrates a cross sectionorthogonal to the medium facing surface and the plane of a substrate.The arrow indicated with T in FIG. 1 shows the direction of travel of arecording medium. The arrow with T denotes the same in the otherdrawings, too. FIG. 2 is a front view of the medium facing surface ofthe magnetic head of the embodiment. FIG. 3 is a top view of a polelayer of the magnetic head of the embodiment.

As shown in FIG. 1 and FIG. 2, the magnetic head for perpendicularmagnetic recording (hereinafter simply called the magnetic head) of theembodiment comprises: a substrate 1 made of a ceramic such as aluminumoxide and titanium carbide (Al₂O₃—TiC); an insulating layer 2 made of aninsulating material such as alumina (Al₂O₃) and disposed on thesubstrate 1; a bottom shield layer 3 made of a magnetic material anddisposed on the insulating layer 2; a bottom shield gap film 4 that isan insulating film disposed on the bottom shield layer 3; amagnetoresistive (MR) element 5 as a read element disposed on the bottomshield gap film 4; a top shield gap film 6 that is an insulating filmdisposed on the MR element 5; and a top shield layer 7 made of amagnetic material and disposed on the top shield gap film 6.

The MR element 5 has an end that is located in the medium facing surface30 that faces toward a recording medium. The MR element 5 may be anelement made of a magneto-sensitive film that exhibits amagnetoresistive effect, such as an anisotropic magnetoresistive (AMR)element, a giant magnetoresistive (GMR) element, or a tunnelmagnetoresistive (TMR) element. The GMR element may be of acurrent-in-plane (CIP) type wherein a current used for detectingmagnetic signals is fed in the direction nearly parallel to the plane ofeach layer making up the GMR element, or may be of acurrent-perpendicular-to-plane (CPP) type wherein a current used fordetecting magnetic signals is fed in the direction nearly perpendicularto the plane of each layer making up the GMR element.

The portions from the bottom shield layer 3 to the top shield layer 7make up a read head. The magnetic head further comprises a nonmagneticlayer 8 made of a nonmagnetic material and disposed on the top shieldlayer 7, and a write head disposed on the nonmagnetic layer 8. Thenonmagnetic layer 8 is made of alumina, for example.

The write head comprises a first coil 11, a second coil 23, a magneticlayer 18 for writing, a first magnetic layer 9 for flux concentration, asecond magnetic layer 20 for flux concentration, and a gap layer 19. Thefirst coil 11 and the second coil 23 each generate a magnetic fieldcorresponding to data to be written on the recording medium.

The magnetic layer 18 for writing has an end face located in the mediumfacing surface 30. The magnetic layer 18 for writing allows a magneticflux corresponding to the field generated by each of the coils 11 and 23to pass therethrough and generates a write magnetic field for writingthe data on the medium by means of the perpendicular magnetic recordingsystem. The magnetic layer 18 for writing incorporates: a pole layer 18Ahaving the end face located in the medium facing surface 30; and anupper yoke layer 18B connected to the pole layer 18A and disposedforward of the pole layer 18A along the direction T of travel of therecording medium at a location away from the medium facing surface 30.

The first magnetic layer 9 for flux concentration is disposed backwardof the magnetic layer 18 for writing along the direction T of travel ofthe recording medium and connected to the pole layer 18A of the magneticlayer 18 at a location away from the medium facing surface 30. The firstmagnetic layer 9 for flux concentration allows a magnetic fluxcorresponding to the field generated by the first coil 11 to pass. Thefirst magnetic layer 9 for flux concentration incorporates: a firstlayer 9A having an end face located in the medium facing surface 30; anda second layer 9B connected to the top surface of the first layer 9A ata location away from the medium facing surface 30. The top surface ofthe second layer 9B is connected to a region of the bottom surface ofthe pole layer 18A away from the medium facing surface 30.

The second magnetic layer 20 for flux concentration is disposed forwardof the magnetic layer 18 for writing along the direction T of travel ofthe recording medium and connected to the upper yoke layer 18B of themagnetic layer 18 at a location away from the medium facing surface 30.The second magnetic layer 20 for flux concentration allows a magneticflux corresponding to the field generated by the second coil 23 to pass.The second magnetic layer 20 for flux concentration incorporates: afirst layer 20A having an end face located in the medium facing surface30; and a second layer 20B having an end face located in the mediumfacing surface, the second layer 20B being connected to the top surfaceof the first layer 20A and also connected to a region of the top surfaceof the upper yoke layer 18B away from the medium facing surface 30.

Each of the layers making up the magnetic layers 9 and 20 is made of amagnetic material. The material may be any of CoFeN, CoNiFe, NiFe andCoFe, for example.

The magnetic head further comprises an insulating layer 10 made of aninsulating material and disposed around the second layer 9B on the firstlayer 9A. The insulating layer 10 is made of alumina, for example. Thefirst coil 11 is disposed on the insulating layer 10. The coil 11 isflat-whorl-shaped. The coil 11 is made of a conductive material such ascopper. When seen in a direction orthogonal to the interface between thefirst magnetic layer 9 and the magnetic layer 18, that is, the interfaceS1 between the second layer 9B and the pole layer 18A, (seen from thetop or bottom of FIG. 1), the coil 11 is wound around the interface S1.

The magnetic head further comprises: an insulating layer 12 made of aninsulating material and disposed around the coil 11 and in the spacebetween the respective adjacent turns of the coil 11; and an insulatinglayer 13 disposed around the insulating layer 12 and the second layer9B. The second layer 9B, the coil 11, and the insulating layers 12 and13 have flattened top surfaces. The insulating layer 12 is made ofphotoresist, for example. The insulating layer 13 is made of alumina,for example.

The magnetic head further comprises an encasing layer 14 made of anonmagnetic material and disposed on the flattened top surfaces of thesecond layer 9B, the coil 11, and the insulating layers 12 and 13. Theencasing layer 14 has a groove 14 a that opens in the top surfacethereof and that accommodates at least part of the pole layer 18A. Thebottom of the groove 14 a has a contact hole formed to a level of thetop surface of the second layer 9B. The encasing layer 14 may be made ofan insulating material such as alumina, silicon oxide (SiO_(x)), orsilicon oxynitride (SiON), or a nonmagnetic metal material such as Ru,Ta, Mo, Ti, W, NiCu, NiB or NiP.

The magnetic head further comprises a nonmagnetic metal layer 15 made ofa nonmagnetic metal material and disposed on the top surface of theencasing layer 14. The nonmagnetic metal layer 15 has an opening 15 athat penetrates, and the edge of the opening 15 a is located directlyabove the edge of the groove 14 a in the top surface of the encasinglayer 14. The nonmagnetic metal layer 15 may be made of any of Ta, Mo,W, Ti, Ru, Rh, Re, Pt, Pd, Ir, NiCr, NiP, NiB, AlCu, WSi₂, TaSi₂, TiSi₂,TiN, and TiW, for example.

The magnetic head further comprises a nonmagnetic film 16 and apolishing stopper layer 17 that are disposed in the groove 14 a of theencasing layer 14 and in the opening 15 a of the nonmagnetic metal layer15. The nonmagnetic film 16 is disposed to touch the surface of thegroove 14 a. The pole layer 18A is disposed apart from the surface ofthe groove 14 a. The polishing stopper layer 17 is disposed between thenonmagnetic film 16 and the pole layer 18A. The nonmagnetic film 16 andthe polishing stopper layer 17 have contact holes, too, that are formedto the level of the top surface of the second layer 9B. The pole layer18A is thus connected to the second layer 9B through the contact holesformed in the groove 14 a, the nonmagnetic film 16 and the polishingstopper layer 17.

As described above, the pole layer 18A is disposed in the groove 14 a ofthe encasing layer 14 and in the opening 15 a of the nonmagnetic metallayer 15 with the nonmagnetic film 16 and the polishing stopper layer 17disposed between the pole layer 18A and each of the groove 14 a and theopening 15 a. The nonmagnetic film 16 has a thickness that falls withina range of 10 to 40 nm inclusive, for example. However, the thickness ofthe nonmagnetic film 16 is not limited to this range but may be of anyother value, depending on the track width. The polishing stopper layer17 has a thickness that falls within a range of 30 to 100 nm inclusive,for example.

The nonmagnetic film 16 is made of a nonmagnetic material. The materialof the nonmagnetic film 16 may be an insulating material, asemiconductor material or a conductive material. The insulating materialas the material of the nonmagnetic film 16 may be any of alumina,silicon oxide (SiO_(x)), and silicon oxynitride (SiON). Thesemiconductor material as the material of the nonmagnetic film 16 may bepolycrystalline silicon or amorphous silicon. The conductive material asthe material of the nonmagnetic film 16 may be the same as that of thenonmagnetic metal layer 15.

The polishing stopper layer 17 is made of a nonmagnetic material. Thematerial of the polishing stopper layer 17 may be a nonmagneticconductive material or an insulating material. The nonmagneticconductive material as the material of the polishing stopper layer 17may be the same as that of the nonmagnetic metal layer 15. Theinsulating material as the material of the polishing stopper layer 17may be silicon oxide.

The pole layer 18A is made of a magnetic metal material. The pole layer18A may be made of any of NiFe, CoNiFe and CoFe, for example.

The gap layer 19 is disposed on a region of the pole layer 18A near themedium facing surface 30. The gap layer 19 is made of a nonmagneticmaterial. The material of the gap layer 19 may be an insulating materialsuch as alumina or a nonmagnetic conductive material such as Ru, NiCu,Ta, W, NiB or NiP.

The first layer 20A of the magnetic layer 20 for flux concentration isdisposed on the gap layer 19. In the medium facing surface 30, the endface of the first layer 20A is located at a specific distance created bythe thickness of the gap layer 19 from the end face of the pole layer18A. The thickness of the gap layer 19 preferably falls within a rangeof 5 to 60 nm inclusive, and may fall within a range of 30 to 60 nminclusive, for example. The end face of the pole layer 18A has a sideadjacent to the gap layer 19, and this side defines the track width.

The first layer 20A may incorporate: a middle portion including aportion opposed to the pole layer 18A with the gap layer 19 disposed inbetween; and two side portions located outside the middle portion alongthe direction of track width. The maximum length of each of the sideportions taken in the direction orthogonal to the medium facing surface30 is greater than the length of the middle portion taken in thedirection orthogonal to the medium facing surface 30.

The upper yoke layer 18B is disposed on a region of the pole layer 18Aaway from the medium facing surface 30 and connected to the pole layer18A. The magnetic head further comprises a nonmagnetic layer 21 made ofa nonmagnetic material and disposed around the first layer 20A and theupper yoke layer 18B. The nonmagnetic layer 21 is made of alumina, forexample. The first layer 20A, the upper yoke layer 18B and thenonmagnetic layer 21 have flattened top surfaces.

The magnetic head further comprises an insulating layer 22 made of aninsulating material and disposed on portions of the flattened topsurfaces of the upper yoke layer 18B and the nonmagnetic layer 21. Theinsulating layer 22 is made of alumina, for example. The second coil 23is disposed on the insulating layer 22. The coil 23 isflat-whorl-shaped. The coil 23 is made of a conductive material such ascopper.

The magnetic head further comprises an insulating layer 24 made of aninsulating material and disposed around the coil 23 and in the spacebetween the respective adjacent turns of the coil 23. The insulatinglayer 24 is made of photoresist, for example. The second layer 20B isdisposed to couple the first layer 20A to the upper yoke layer 18B. Aportion of the second layer 20B is disposed on the insulating layer 24.When seen in the direction orthogonal to the interface between thesecond magnetic layer 20 and the magnetic layer 18, that is, theinterface S2 between the second layer 20B and the upper yoke layer 18B,(seen from the top or bottom of FIG. 1), the coil 23 is wound around theinterface S2. When seen in the direction orthogonal to the interface S2,the interface S2 is disposed at a location that is closer to the mediumfacing surface 30 than the interface S1 and that does not coincide withthe interface S1.

Part of the coil 23 is disposed between the second layer 20B of themagnetic layer 20 and the yoke layer 18B of the magnetic layer 18.

The magnetic head further comprises a protection layer 25 made of anonmagnetic material and disposed to cover the second layer 20B. Theprotection layer 25 is made of an inorganic insulating material such asalumina.

As described so far, the magnetic head of the embodiment comprises themedium facing surface 30 that faces toward a recording medium, the readhead, and the write head. The read head and the write head are stackedon the substrate 1. The read head is located backward along thedirection T of travel of the recording medium (that is, located closerto the air inflow end of the slider). The write head is located forwardalong the direction T of travel of the recording medium (that is,located closer to the air outflow end of the slider).

The read head comprises the MR element 5 as the read element, and thebottom shield layer 3 and the top shield layer 7 for shielding the MRelement 5. Portions of the bottom shield layer 3 and the top shieldlayer 7 that are located on a side of the medium facing surface 30 areopposed to each other, the MR element 5 being placed between theseportions. The read head further comprises: the bottom shield gap film 4disposed between the MR element 5 and the bottom shield layer 3; and thetop shield gap film 6 disposed between the MR element 5 and the topshield layer 7.

The write head comprises the first coil 11, the second coil 23, themagnetic layer 18 for writing, the first magnetic layer 9 for fluxconcentration, the second magnetic layer 20 for flux concentration, andthe gap layer 19. The magnetic layer 18 for writing incorporates: thepole layer 18A having the end face located in the medium facing surface30; and the upper yoke layer 18B connected to the pole layer 18A anddisposed forward of the pole layer 18A along the direction T of travelof the recording medium at a location away from the medium facingsurface 30.

The first magnetic layer 9 for flux concentration is disposed backwardof the magnetic layer 18 for writing along the direction T of travel ofthe recording medium and connected to the pole layer 18A of the magneticlayer 18 at a location away from the medium facing surface 30. The firstmagnetic layer 9 allows a magnetic flux corresponding to the fieldgenerated by the first coil 11 to pass. The first magnetic layer 9incorporates: the first layer 9A having the end face located in themedium facing surface 30; and the second layer 9B connected to a regionof the top surface of the first layer 9A away from the medium facingsurface 30. The magnetic layer 9 incorporates a portion located tosandwich part of the coil 11 between the magnetic layer 18 and itself,that is, the first layer 9A. The magnetic layer 9 and the second layer9B thereof, in particular, have a function of allowing the magnetic fluxcorresponding to the field generated by the coil 11 to concentrate inthe magnetic layer 9.

The second magnetic layer 20 for flux concentration is disposed forwardof the magnetic layer 18 for writing along the direction T of travel ofthe recording medium and connected to the upper yoke layer 18B of themagnetic layer 18 at a location away from the medium facing surface 30.The second magnetic layer 20 allows a magnetic flux corresponding to thefield generated by the second coil 23 to pass. The second magnetic layer20 incorporates: the first layer 20A having the end face located in themedium facing surface 30; and the second layer 20B having the end facelocated in the medium facing surface 30, the second layer 20B beingconnected to the top surface of the first layer 20A and also connectedto a region of the top surface of the upper yoke layer 18B away from themedium facing surface 30. Part of the coil 23 is disposed between thesecond layer 20B of the magnetic layer 20 and the upper yoke layer 18Bof the magnetic layer 18. The magnetic layer 20 and a portion of thesecond layer 20B thereof located in the center portion of the coil 23,in particular, have a function of allowing the magnetic fluxcorresponding to the field generated by the coil 23 to concentrate inthe magnetic layer 20.

When seen in the direction orthogonal to the interface S2 between thesecond layer 20B and the upper yoke layer 18B, the interface S2 isdisposed at a location that is closer to the medium facing surface 30than the interface S1 between the second layer 9B and the pole layer 18Aand that does not coincide with the interface S1.

Reference is now made to FIG. 2 and FIG. 3 to describe the shape of thepole layer 18A in detail. As shown in FIG. 3, the pole layer 18Aincorporates a track width defining portion 18A1 and a wide portion18A2. The track width defining portion 18A1 has the end face located inthe medium facing surface 30. The wide portion 18A2 is located fartherfrom the medium facing surface 30 than the track width defining portion18A1 and has a width greater than the width of the track width definingportion 18A1. The width of the track width defining portion 18A1 doesnot change in accordance with the distance from the medium facingsurface 30. For example, the wide portion 18A2 is equal in width to thetrack width defining portion 18A1 at the boundary with the track widthdefining portion 18A1, and gradually increases in width as the distancefrom the medium facing surface 30 increases and then maintains aspecific width to the end of the wide portion 18A2. In the embodimentthe track width defining portion 18A1 is a portion of the pole layer 18Aextending from the end face located in the medium facing surface 30 tothe point at which the width of the pole layer 18A starts to increase.Here, the length of the track width defining portion 18A1 taken in thedirection orthogonal to the medium facing surface 30 is called a neckheight and indicated with NH. The neck height NH falls within a range of0.05 to 0.3 μm inclusive, for example.

As shown in FIG. 2, the end face of the pole layer 18A located in themedium facing surface 30 has: a first side A1 closest to the substrate1; a second side A2 adjacent to the gap layer 19; a third side A3connecting an end of the first side A1 to an end of the second side A2;and a fourth side A4 connecting the other end of the first side A1 tothe other end of the second side A2. The second side A2 defines thetrack width. The width of the end face of the pole layer 18A located inthe medium facing surface 30 decreases as the distance from the gaplayer 19 increases. Each of the third side A3 and the fourth side A4forms an angle that falls within a range of 5 to 15 degrees inclusive,for example, with respect to the direction orthogonal to the top surfaceof the substrate 1. The length of the second side A2, that is, the trackwidth, falls within a range of 0.05 to 0.20 μm inclusive, for example.

In the embodiment, as shown in FIG. 1, the throat height TH is thedistance between the medium facing surface 30 and a point at which thespace between the pole layer 18A and the magnetic layer 20 starts toincrease when seen from the medium facing surface 30. The throat heightTH falls within a range of 0.05 to 0.3 μm inclusive, for example.

Reference is now made to FIG. 4A to FIG. 10A and FIG. 4B to FIG. 10B todescribe a method of manufacturing the magnetic head of the embodiment.FIG. 4A to FIG. 10A each illustrate a cross section of a layeredstructure obtained in manufacturing process of the magnetic head, thecross section being orthogonal to the medium facing surface and thesubstrate. FIG. 4B to FIG. 10B each illustrate a cross section of aportion of the layered structure near the medium facing surface, thecross section being parallel to the medium facing surface. The portionscloser to the substrate 1 than the first layer 9A of the first magneticlayer 9 are omitted in FIG. 4A to FIG. 10A and FIG. 4B to FIG. 10B.

According to the method of manufacturing the magnetic head of theembodiment, as shown in FIG. 1, the insulating layer 2, the bottomshield layer 3 and the bottom shield gap film 4 are first formed one byone on the substrate 1. Next, the MR element 5 and leads (not shown)connected to the MR element 5 are formed on the bottom shield gap film4. Next, the top shield gap film 6 is formed to cover the MR element 5and the leads. Next, the top shield layer 7, the nonmagnetic layer 8 andthe first layer 9A are formed one by one on the top shield gap film 6.

FIG. 4A and FIG. 4B illustrate the following step. In the step, first,the insulating layer 10 is selectively formed on a region of the topsurfaces of the first layer 9A where the coil 11 is to be disposed.Next, the coil 11 is formed on the insulating layer 10 by frame plating,for example. Next, the second layer 9B is formed on the first layer 9Aby frame plating, for example. Alternatively, the coil 11 may be formedafter the second layer 9B is formed.

Next, the insulating layer 12 made of photoresist, for example, isselectively formed around the coil 11 and in the space between therespective adjacent turns of the coil 11. Next, the insulating layer 13is formed by a method such as sputtering on the entire top surface ofthe layered structure. Next, the insulating layer 13 is polished bychemical mechanical polishing (hereinafter referred to as CMP), forexample, so that the second layer 9B and the coil 11 are exposed, andthe top surfaces of the second layer 9B, the coil 11, and the insulatinglayers 12 and 13 are thereby flattened.

FIG. 5A and FIG. 5B illustrate the following step. In the step, first, anonmagnetic layer 14P is formed on the flattened top surfaces of thecoil 11 and the insulating layers 12 and 13. The groove 14 a will beformed in the nonmagnetic layer 14P later and the nonmagnetic layer 14Pwill be thereby formed into the encasing layer 14. Next, the nonmagneticmetal layer 15 made of a nonmagnetic metal material is formed bysputtering, for example, on the nonmagnetic layer 14P. The nonmagneticmetal layer 15 has a thickness that falls within a range of 20 to 100 nminclusive, for example.

Next, a photoresist layer having a thickness of 1.0 μm, for example, isformed on the nonmagnetic metal layer 15. The photoresist layer is thenpatterned to form a mask 31 for making the groove 14 a of the encasinglayer 14. The mask 31 has an opening having a shape corresponding to thegroove 14 a.

Next, the nonmagnetic metal layer 15 is selectively etched using themask 31. The opening 15 a that penetrates is thereby formed in thenonmagnetic metal layer 15. The opening 15 a has a shape correspondingto the plane geometry of the pole layer 18A to be formed later.Furthermore, a portion of the nonmagnetic layer 14P exposed from theopening 15 a of the nonmagnetic metal layer 15 is selectively etched soas to form the groove 14 a in the nonmagnetic layer 14P. Furthermore, aportion of the nonmagnetic layer 14P located on the second layer 9B isselectively etched so as to form a contact hole at the bottom of thegroove 14 a. The mask 31 is then removed. The nonmagnetic layer 14P isformed into the encasing layer 14 by being provided with the groove 14a. The edge of the opening 15 a of the nonmagnetic metal layer 15 islocated directly above the edge of the groove 14 a located in the topsurface of the encasing layer 14.

The etching of the nonmagnetic metal layer 15 and the nonmagnetic layer14P is performed by reactive ion etching or ion beam etching, forexample. The etching for forming the groove 14 a in the nonmagneticlayer 14P is performed such that the walls of the groove 14 acorresponding to both sides of the track width defining portion 18A1 ofthe pole layer 18A each form an angle that falls within a range of 5 to15 degrees inclusive, for example, with respect to the directionorthogonal to the top surface of the substrate 1.

FIG. 6A and FIG. 6B illustrate the following step. In the step, first,the nonmagnetic film 16 is formed on the entire top surface of thelayered structure. The nonmagnetic film 16 is formed in the groove 14 aof the encasing layer 14, too. The nonmagnetic film 16 is formed bysputtering or chemical vapor deposition (hereinafter referred to asCVD), for example. It is possible to control the thickness of thenonmagnetic film 16 with precision. It is thereby possible to controlthe track width with accuracy. In the case of forming the nonmagneticfilm 16 by CVD, it is preferred to employ a method called ‘atomic layerCVD’ (ALCVD) in which formation of a single atomic layer is repeated. Inthis case, it is possible to control the thickness of the nonmagneticfilm 16 with higher precision. In the case of forming the nonmagneticfilm 16 by ALCVD, the material of the nonmagnetic film 16 is preferablyalumina among insulating materials, or Ta or Ru among conductivematerials. If a semiconductor material is selected as the material ofthe nonmagnetic film 16, it is preferred to form the nonmagnetic film 16by ALCVD at a low temperature (around 200° C.) or by low-pressure CVD ata low temperature. The semiconductor material as the material of thenonmagnetic film 16 is preferably undoped polycrystalline silicon oramorphous silicon.

Next, the polishing stopper layer 17 is formed on the entire top surfaceof the layered structure. The polishing stopper layer 17 is formed inthe groove 14 a of the encasing layer 14, too. The polishing stopperlayer 17 indicates the level at which polishing of the polishing step tobe performed later is stopped. If the nonmagnetic film 16 is made of aconductive material, it is possible to make the nonmagnetic film 16function as the polishing stopper layer 17, too, without providing thepolishing stopper layer 17.

If a nonmagnetic conductive material is selected as the material of thepolishing stopper layer 17, the polishing stopper layer 17 is formed bysputtering or CVD, for example. In the case of forming the polishingstopper layer 17 by CVD, it is preferred to employ ALCVD. In the case offorming the polishing stopper layer 17 by ALCVD using a nonmagneticconductive material, Ta or Ru is preferred as the material of thepolishing stopper layer 17. The polishing stopper layer 17 formed byALCVD exhibits a good step coverage. Therefore, it is possible to formthe polishing stopper layer 17 that is uniform in the groove 14 a of theencasing layer 14 by employing ALCVD to form the polishing stopper layer17. It is thereby possible to control the track width with accuracy. Inthe case of forming the polishing stopper layer 17 by ALCVD, thenonmagnetic film 16 for controlling the track width may be omitted.

If the polishing stopper layer 17 is formed by ALCVD using a nonmagneticconductive material, it is possible to reduce the resistance of theelectrode layer (seed layer) used for forming the pole layer 18A byplating. It is thereby possible to form the pole layer 18A having aprecise thickness.

Next, portions of the nonmagnetic film 16 and the polishing stopperlayer 17 located on the second layer 9B are selectively etched to formthe contact holes in the nonmagnetic film 16 and the polishing stopperlayer 17.

FIG. 7A and FIG. 7B illustrate the following step. In the step, first, amagnetic layer not shown that will be the pole layer 18A later is formedon the entire top surface of the layered structure. This magnetic layeris formed by the following method, for example. First, an electrode filmnot shown that is to be a portion of an electrode layer (seed layer) forplating is formed on the entire top surface of the layered structure.The electrode film is made of a magnetic material and will be a portionof the pole layer 18A later. The electrode film is formed by sputteringor ion beam deposition, for example. In the case of forming theelectrode film by sputtering, it is preferred to employ collimationsputtering or long throw sputtering. Alternatively, the polishingstopper layer 17 may be used as the electrode layer (seed layer) forplating instead of forming the electrode film made of a magneticmaterial. Next, a plating layer is formed on the electrode film by frameplating, for example. The plating layer has a thickness of 0.5 to 1.0μm, for example. The plating layer is made of a magnetic material andwill be a major portion of the pole layer 18A later. The plating layeris formed such that the top surface thereof is located higher than thetop surfaces of the nonmagnetic metal layer 15, the nonmagnetic film 16and the polishing stopper layer 17. Next, a coating layer not shown madeof alumina, for example, and having a thickness of 0.5 to 1.2 μm forexample, is formed by a method such as sputtering on the entire topsurface of the layered structure. Next, the coating layer and themagnetic layer are polished by CMP, for example, so that the polishingstopper layer 17 is exposed, and the top surfaces of the polishingstopper layer 17 and the magnetic layer are thereby flattened. In thecase of polishing the coating layer and the magnetic layer by CMP, sucha slurry is used that polishing is stopped when the polishing stopperlayer 17 is exposed, such as an alumina-base slurry.

FIG. 8A and FIG. 8B illustrate the following step. In the step, first,the gap layer 19 is formed on the entire top surface of the layeredstructure. The gap layer 19 is formed by sputtering or CVD, for example.In the case of forming the gap layer 19 by CVD, it is preferred toemploy ALCVD. In the case of forming the gap layer 19 by ALCVD, thematerial of the gap layer 19 is preferably alumina among insulatingmaterials, or Ta or Ru among conductive materials. Next, a photoresistlayer is formed on the entire top surface of the layered structure. Thephotoresist layer is then patterned to form a mask not shown. The maskcovers a portion of the gap layer 19 to be left. Next, the gap layer 19is selectively etched using the mask. Next, the mask is removed.

Next, the first layer 20A is formed on the gap layer 19, and the upperyoke layer 18B is formed on the pole layer 18A. The first layer 20A andthe upper yoke layer 18B may be formed by frame plating or by making amagnetic layer through sputtering and then selectively etching themagnetic layer. Selective etching of the magnetic layer may be performedby forming an alumina layer on the magnetic layer, making a mask on thealumina layer by frame plating, and etching the alumina layer and themagnetic layer using the mask.

Next, the nonmagnetic layer 21 is formed on the entire top surface ofthe layered structure. Next, the nonmagnetic layer 21 is polished byCMP, for example, so that the first layer 20A and the upper yoke layer18B are exposed, and the top surfaces of the first layer 20A, the upperyoke layer 18B and the nonmagnetic layer 21 are thereby flattened.

FIG. 9A and FIG. 9B illustrate the following step. In the step, first,the insulating layer 22 is formed on regions of the top surfaces of theupper yoke layer 18B and the nonmagnetic layer 21 where the coil 23 isto be disposed. Next, the coil 23 is formed on the insulating layer 22by frame plating, for example.

FIG. 10A and FIG. 10B illustrate the following step. In the step, first,the insulating layer 24 is formed to cover the coil 23. Next, the secondlayer 20B is formed by frame plating, for example.

Next, as shown in FIG. 1, the protection layer 25 is formed to cover theentire top surface of the layered structure. Wiring and terminals arethen formed on the protection layer 25, the substrate is cut intosliders, and the steps including polishing of the medium facing surface30 and fabrication of flying rails are performed. The magnetic head isthus completed.

The operation and effects of the magnetic head of the embodiment willnow be described. The magnetic head writes data on a recording medium byusing the write head and reads data written on the recording medium byusing the read head. In the write head the coils 11 and 23 each generatea magnetic field that corresponds to the data to be written on themedium. A magnetic flux corresponding to the magnetic field generated bythe coil 11 passes through the first magnetic layer 9 for fluxconcentration and the magnetic layer 18 for writing. A magnetic fluxcorresponding to the magnetic field generated by the coil 23 passesthrough the second magnetic layer 20 for flux concentration and themagnetic layer 18 for writing. Therefore, the magnetic layer 18 allowsthe flux corresponding to the field generated by the coil 11 and theflux corresponding to the field generated by the coil 23 to pass.

The coils 11 and 23 may be connected to each other either in series orparallel. In either case, the coils 11 and 23 are connected to eachother in such a manner that, in the magnetic layer 18, the fluxcorresponding to the field generated by the coil 11 and the fluxcorresponding to the field generated by the coil 23 flow in the samedirection. In FIG. 1 the arrows in the first magnetic layer 9, themagnetic layer 18 and the second magnetic layer 20 schematically showthe directions in which the fluxes flow.

As described above, the magnetic layer 18 allows the flux correspondingto the field generated by each of the coils 11 and 23 to pass andgenerates from the end face of the pole layer 18A located in the mediumfacing surface 30 a write magnetic field used for writing the data onthe recording medium by means of the perpendicular magnetic recordingsystem.

The first magnetic layer 9 and the second magnetic layer 20 eachfunction as a shield. That is, the magnetic layers 9 and 20 take in adisturbance magnetic field applied from outside the magnetic head to themagnetic head. It is thereby possible to prevent erroneous writing onthe recording medium caused by the disturbance magnetic fieldintensively taken in into the pole layer 18A. Furthermore, the magneticlayers 9 and 20 have a function of taking in a magnetic flux that isgenerated from the end face of the pole layer 18A and that extends indirections except the direction orthogonal to the surface of therecording medium, and preventing this flux from reaching the recordingmedium. The magnetic layers 9 and 20 also have a function of returning amagnetic flux that has been generated from the end face of the polelayer 18A and has magnetized the recording medium.

The first magnetic layer 9 is located backward of the pole layer 18Aalong the direction T of travel of the recording medium. The secondmagnetic layer 20 is located forward of the pole layer 18A along thedirection T of travel of the recording medium. Therefore, according tothe embodiment, in regions both forward and backward of the end face ofthe pole layer 18A along the direction T of travel of the recordingmedium, it is possible to take in the magnetic flux generated from theend face of the pole layer 18A and extending in directions except thedirection orthogonal to the surface of the recording medium, and tothereby prevent this flux from reaching the recording medium. As aresult, according to the embodiment, over a wide range along thedirection of track with, it is possible to suppress a phenomenon ofattenuation of signals written on one or more tracks adjacent to thetrack that is a target of writing or reading.

According to the embodiment, the magnetic fluxes corresponding to themagnetic fields generated by the two coils 11 and 23 pass through thepole layer 18A. As a result, it is possible to make the number of turnsof each of the coils 11 and 23 smaller than that of a single coil of amagnetic head in which the coil is the only one coil provided. It isthereby possible to reduce the resistance of each of the coils 11 and 23and to thereby reduce the heat value of each of the coils 11 and 23. Asa result, according to the embodiment, it is possible to suppressprotrusion of a portion of the medium facing surface 30 due to the heatgenerated by the coils 11 and 23.

The location of an end of a bit pattern to be written on the recordingmedium is determined by the location of the end of the end face of thepole layer 18A located in the medium facing surface 30, the end beinglocated forward along the direction T of travel of the recording medium.Therefore, to define the location of the end of the bit patternprecisely, it is important to take in a magnetic flux particularly at alocation forward of the end face of the pole layer 18A along thedirection T of travel of the recording medium, the flux being generatedfrom the end face of the pole layer 18A and extending in directionsexcept the direction orthogonal to the surface of the recording medium,so as to prevent the flux from reaching the recording medium. In theembodiment, the first layer 20A of the second magnetic layer 20 has anend face located in the medium facing surface 30. The end face of thefirst layer 20A is located forward of the end face of the pole layer 18Aalong the direction T of travel of the recording medium with a specificsmall space created by the thickness of the gap layer 19. As a result,particularly at a location forward of the end face of the pole layer 18Aalong the direction T of travel of the recording medium, it is possibleto effectively take in the magnetic flux generated from the end face ofthe pole layer 18A and extending in directions except the directionorthogonal to the surface of the recording medium, and to therebyprevent the flux from reaching the recording medium. As a result,according to the embodiment, it is possible to precisely define thelocation of the end of the bit pattern to be written on the medium.According to the embodiment, an improvement in linear recording densityis thereby achieved.

According to the embodiment, as shown in FIG. 2, the end face of thepole layer 18A located in the medium facing surface 30 has a width thatdecreases as the distance from the gap layer 19 increases. It is therebypossible to prevent the problems resulting from the skew.

According to the embodiment, the pole layer 18A is disposed in thegroove 14 a of the encasing layer 14 made of a nonmagnetic material, thenonmagnetic film 16 and the polishing stopper layer 17 being disposedbetween the pole layer 18A and the groove 14 a. Consequently, the polelayer 18A is smaller than the groove 14 a in width. It is therebypossible to easily form the groove 14 a and to easily reduce the widthof the pole layer 18A and the width of the top surface of the trackwidth defining portion 18A1 that defines the track width, in particular.As a result, according to the embodiment, it is possible to easilyimplement the track width that is smaller than the minimum track widththat can be formed by photolithography and to control the track widthwith accuracy.

Reference is now made to FIG. 11 to describe a reference magnetic head.FIG. 11 is a cross-sectional view for illustrating the configuration ofthe reference magnetic head. In the reference magnetic head, when seenin the direction orthogonal to the interface S2 between the second layer20B and the upper yoke layer 18B, the interface S2 is located tocoincide with the interface S1 between the second layer 9B and the polelayer 18A. The remainder of configuration of the reference magnetic headis the same as that of the magnetic head of the embodiment. In FIG. 11the arrows in the first magnetic layer 9, the magnetic layer 18 and thesecond magnetic layer 20 schematically show the directions in whichmagnetic fluxes flow. In the reference magnetic head, in the regionbetween the interfaces S1 and S2 in the magnetic layer 18, the flow ofthe magnetic flux that has come into the pole layer 18A from the secondlayer 9B and the flow of the magnetic flux that has come into the upperyoke layer 18B from the second layer 20B are nearly opposite indirection. As a result, in the magnetic layer 18 of the referencemagnetic head, the flux that has come into the pole layer 18A from thesecond layer 9B and the flux that has come into the upper yoke layer 18Bfrom the second layer 20B repel each other, and the flux density of themagnetic layer 18 may be thereby reduced, which may result indegradation of the overwrite property.

According to the embodiment, in contrast, when seen in the directionorthogonal to the interface S2 between the second layer 20B and theupper yoke layer 18B, the interface 52 is disposed at a location that iscloser to the medium facing surface 30 than the interface S1 between thesecond layer 9B and the pole layer 18A and that does not coincide withthe interface S1. As a result, in the embodiment, in a region of themagnetic layer 18 that coincides with the interface S2 when seen in thedirection orthogonal to the interface S2, the flux that has come intothe pole layer 18A from the second layer 9B flows in a nearly horizontaldirection, which is not opposite to the direction of the flow of theflux that has come into the upper yoke layer 18B from the second layer20B. Consequently, according to the embodiment, in the magnetic layer18, it is possible to suppress repulsion between the flux that has comeinto the pole layer 18A from the second layer 9B and the flux that hascome into the upper yoke layer 18B from the second layer 20B. It isthereby possible to prevent a reduction in flux density of the magneticlayer 18 and to thereby improve the overwrite property.

In the embodiment the interface S2 may be disposed at a location that isfarther from the medium facing surface 30 than the interface S1 and thatdoes not coincide with the interface S1. In this case, in the region ofthe magnetic layer 18 that coincides with the interface S1 when seen inthe direction orthogonal to the interface S1, the flux that has comeinto the upper yoke layer 18B from the second layer 20B flows in anearly horizontal direction, which is not opposite to the direction offlow of the flux that has come into the pole layer 18A from the secondlayer 9B. Therefore, in this case, too, in the magnetic layer 18, it ispossible to suppress repulsion between the flux that has come into thepole layer 18A from the second layer 9B and the flux that has come intothe upper yoke layer 18B from the second layer 20B, and to therebyprevent a reduction in flux density of the magnetic layer 18. As aresult, it is possible to improve the overwrite property.

In the embodiment, the end face of the first layer 9A closer to themedium facing surface 30 may be located at a distance from the mediumfacing surface 30.

In the embodiment, the second layer 20B may be directly connected to thepole layer 18A without providing the upper yoke layer 18B. In this case,it suffices that, when seen in the direction orthogonal to the interfacebetween the second layer 20B and the pole layer 18A, this interface isdisposed at a location that does not coincide with the interface S1between the second layer 9B and the pole layer 18A.

Second Embodiment

Reference is now made to FIG. 12 to describe a magnetic head of a secondembodiment of the invention. FIG. 12 is a cross-sectional view forillustrating the configuration of the magnetic head of the secondembodiment. FIG. 12 illustrates a cross section orthogonal to the mediumfacing surface and the plane of the substrate.

In the magnetic head of the second embodiment, the insulating layer 13is provided to cover the first coil 11 and the insulating layer 12. Theinsulating layer 13 and the second layer 9B have flattened top surfaces.

In the second embodiment a lower yoke layer 18C is provided in place ofthe upper yoke layer 18B of the first embodiment. The magnetic layer 18for writing of the second embodiment incorporates the pole layer 18A andthe lower yoke layer 18C. The lower yoke layer 18C is connected to thepole layer 18A and disposed backward of the pole layer 18A along thedirection T of travel of the recording medium at a location away fromthe medium facing surface 30. The lower yoke layer 18C is disposed onthe insulating layer 13 and the second layer 9B.

In the second embodiment the second magnetic layer 20 for fluxconcentration incorporates a third layer 20C in addition to the firstlayer 20A and the second layer 20B of the first embodiment. The thirdlayer 20C is disposed forward of the pole layer 18A along the directionT of travel of the recording medium at a location away from the mediumfacing surface 30. The bottom surface of the third layer 20C isconnected to the pole layer 18A. The top surface of the third layer 20Cis connected to the second layer 20B.

In the second embodiment, an insulating layer 27 is provided in place ofthe nonmagnetic layer 21 of the first embodiment. The insulating layer27 is disposed around the first layer 20A and the third layer 20C. Theinsulating layer 27 is made of alumina, for example. The first layer20A, the third layer 20C and the insulating layer 27 have flattened topsurfaces. In the second embodiment the second coil 23 and the insulatinglayer 24 are disposed on the insulating layer 27.

In the second embodiment, the second layer 9B of the first magneticlayer 9 is connected to the lower yoke layer 18C, and the third layer20C of the second magnetic layer 20 is connected to the pole layer 18A.Each of the lower yoke layer 18C and the third layer 20C is made of amagnetic material. The material may be any of CoFeN, CoNiFe, NiFe andCoFe, for example.

In the second embodiment the interface between the magnetic layer 9 andthe magnetic layer 18 is the interface S3 between the second layer 9Band the lower yoke layer 18C. When seen in the direction orthogonal tothe interface S3, the coil 11 is wound around the interface S3.

In the second embodiment the interface between the second magnetic layer20 and the magnetic layer 18 is the interface S4 between the third layer20C and the pole layer 18A. When seen in the direction orthogonal to theinterface S4, the coil 23 is wound around the interface S4. When seen inthe direction orthogonal to the interface S4, the interface S4 isdisposed at a location that is closer to the medium facing surface 30than the interface S3 and that does not coincide with the interface S3.

The method of manufacturing the magnetic head of the second embodimentwill now be described. In the method of manufacturing the magnetic headof the second embodiment, in the step illustrated in FIG. 4A and FIG.4B, the coil 11 and the second layer 9B are formed such that the topsurface of the coil 11 is located lower than the top surface of thesecond layer 9B (that is, located closer to the substrate 1).

In the following step of the second embodiment, the insulating layer 12made of photoresist, for example, is selectively formed around the coil11 and in the space between the respective adjacent turns of the coil11. Next, the insulating layer 13 is formed on the entire top surface ofthe layered structure. Next, the insulating layer 13 is polished by CMP,for example, so that the second layer 9B is exposed, and the topsurfaces of the second layer 9B and the insulating layer 13 are therebyflattened.

The following steps of the second embodiment are the same as the stepsof the first embodiment illustrated in FIG. 5A to FIG. 10A and FIG. 5Bto FIG. 10B, except differences that will now be described. First, inthe second embodiment, in the step illustrated in FIG. 5A and FIG. 5B,the lower yoke layer 18C is formed before the nonmagnetic layer 14P isformed. The nonmagnetic layer 14P is then formed and the groove 14 a isformed in a manner the same as that of the first embodiment. Next, aportion of the nonmagnetic layer 14P located on the lower yoke layer 18Cis selectively etched to form an opening at the bottom of the groove 14a. In the second embodiment, in the step illustrated in FIG. 6A and FIG.6B, portions of the nonmagnetic film 16 and the polishing stopper layer17 located in the opening at the bottom of the groove 14 a areselectively etched to form openings in the nonmagnetic film 16 and thepolishing stopper layer 17. In the second embodiment, in the stepillustrated in FIG. 8A and FIG. 8B, the third layer 20C is formed inplace of the upper yoke layer 18B, and the insulating layer 27 is formedin place of the nonmagnetic layer 21. In the second embodiment, in thestep illustrated in FIG. 9A and FIG. 9B, the coil 23 is formed on theinsulating layer 27 without forming the insulating layer 22.

In FIG. 12 the arrows in the first magnetic layer 9, the magnetic layer18 and the second magnetic layer 20 schematically show the directions inwhich magnetic fluxes flow. In the second embodiment, when seen in thedirection orthogonal to the interface S4 between the third layer 20C andthe pole layer 18A, the interface S4 is disposed at a location that iscloser to the medium facing surface 30 than the interface S3 between thesecond layer 9B and the lower yoke layer 18C and that does not coincidewith the interface S3. As a result, in the second embodiment, in aregion of the magnetic layer 18 that coincides with the interface S4when seen in the direction orthogonal to the interface S4, the flux thathas come into the lower yoke layer 18C from the second layer 9B flows ina nearly horizontal direction, which is not opposite to the direction offlow of the flux that has come into the pole layer 18A from the thirdlayer 20C. Consequently, according to the embodiment, in the magneticlayer 18, it is possible to suppress repulsion between the flux that hascome into the lower yoke layer 18C from the second layer 9B and the fluxthat has come into the pole layer 18A from the third layer 20C. It isthereby possible to prevent a reduction in flux density of the magneticlayer 18 and to thereby improve the overwrite property.

In the second embodiment the interface S4 may be disposed at a locationthat is farther from the medium facing surface 30 than the interface S3and that does not coincide with the interface S3. The remainder ofconfiguration, function and effects of the second embodiment are similarto those of the first embodiment.

Third Embodiment

Reference is now made to FIG. 13 to FIG. 15 to describe a magnetic headof a third embodiment of the invention and a method of manufacturing thesame. Each of FIG. 13 to FIG. 15 is a cross-sectional view forillustrating the configuration of the magnetic head of the thirdembodiment. Each of FIG. 13 to FIG. 15 illustrates a cross sectionorthogonal to the medium facing surface and the plane of the substrate.

The magnetic head of the third embodiment is similar to the magnetichead of the first embodiment but has differences as will now bedescribed. In the magnetic head of the third embodiment, when seen inthe direction orthogonal to the interface S2 between the second layer20B and the upper yoke layer 18B, at least part of the interface S2 isdisposed at a location that coincides with at least part of theinterface S1 between the second layer 9B and the pole layer 18A. Themagnetic head of the third embodiment has a nonmagnetic layer 28B madeof a nonmagnetic material and disposed between the pole layer 18A andthe upper yoke layer 18B. When seen in the direction orthogonal to theinterface S2, at least part of the nonmagnetic layer 28B is disposed ata location that coincides with at least part of the interface S2. Theupper yoke layer 18B is connected to the pole layer 18A at least at alocation closer to the medium facing surface 30 than the nonmagneticlayer 28B. The nonmagnetic layer 28B may be made of a material the sameas that of the gap layer 19. The nonmagnetic layer 28B has a thicknessequal to or greater than that of the gap layer 19. The thickness of thenonmagnetic layer 28B preferably falls within a range of 0.1 to 0.3 μminclusive.

In the embodiment, when seen in the direction orthogonal to theinterface S2, at least part of the interface S2, at least part of theinterface S1, and at least part of the nonmagnetic layer 28B aredisposed at locations that coincide with one another.

The distance between the medium facing surface 30 and an end of thenonmagnetic layer 28B farther from the medium facing surface 30 ispreferably equal to or greater than the distance between the mediumfacing surface 30 and an end of the interface S2 farther from the mediumfacing surface 30.

FIG. 13 to FIG. 15 illustrate three examples in which the locations ofan end of the nonmagnetic layer 28B closer to the medium facing surface30 are different. In the example of FIG. 13, the distance between themedium facing surface 30 and the end of the nonmagnetic layer 28B closerto the medium facing surface 30 is equal to the distance between themedium facing surface 30 and an end of the interface S2 closer to themedium facing surface 30. In the example of FIG. 14, the distancebetween the medium facing surface 30 and the end of the nonmagneticlayer 28B closer to the medium facing surface 30 is greater than thedistance between the medium facing surface 30 and the end of theinterface S2 closer to the medium facing surface 30. In the example ofFIG. 15, the distance between the medium facing surface 30 and the endof the nonmagnetic layer 28B closer to the medium facing surface 30 issmaller than the distance between the medium facing surface 30 and theend of the interface S2 closer to the medium facing surface 30.

The method of manufacturing the magnetic head of the third embodimentincludes the step of forming the nonmagnetic layer 28B on the pole layer18A before forming the upper yoke layer 18B.

In FIG. 13 to FIG. 15 the arrows in the magnetic layer 9, the magneticlayer 18 and the magnetic layer 20 schematically show the directions inwhich magnetic fluxes flow. If the nonmagnetic layer 28B is notprovided, a magnetic flux that has come into the pole layer 18A from thesecond layer 9B and a magnetic flux that has come into the upper yokelayer 18B from the second layer 20B repel each other in the magneticlayer 18, and the flux density of the magnetic layer 18 may be reduced,which may result in degradation of overwrite property. In the thirdembodiment, in contrast, the nonmagnetic layer 28B is provided betweenthe pole layer 18A and the upper yoke layer 18B in a region where theinterfaces S1 and S2 are opposed to each other. As a result, accordingto the embodiment, it is possible to suppress repulsion between the fluxthat has come into the pole layer 18A from the second layer 9B and theflux that has come into the upper yoke layer 18B from the second layer20B in the magnetic layer 18. It is thereby possible to prevent areduction in flux density of the magnetic layer 18 and to therebyimprove the overwrite property.

The remainder of configuration, function and effects of the thirdembodiment are similar to those of the first embodiment.

Fourth Embodiment

Reference is now made to FIG. 16 to describe a magnetic head of a fourthembodiment of the invention. FIG. 16 is a cross-sectional view forillustrating the configuration of the magnetic head of the fourthembodiment. FIG. 16 illustrates a cross section orthogonal to the mediumfacing surface and the plane of the substrate.

In the magnetic head of the fourth embodiment, an insulating layer 29 isprovided in place of the first layer 9A of the magnetic layer 9 for fluxconcentration of the third embodiment. The insulating layer 29 is madeof alumina, for example. The magnetic layer 9 of the fourth embodimentis made up only of a magnetic layer that is an equivalent of the secondlayer 9B of the first embodiment. In this case, too, the magnetic layer9 has a function of allowing a magnetic flux corresponding to the fieldgenerated by the coil 11 to concentrate in the magnetic layer 9. In FIG.16 the arrows in the first magnetic layer 9, the magnetic layer 18 andthe second magnetic layer 20 schematically show the directions in whichthe fluxes flow.

As does FIG. 13, FIG. 16 shows an example in which the distance betweenthe medium facing surface 30 and the end of the nonmagnetic layer 28Bcloser to the medium facing surface 30 is equal to the distance betweenthe medium facing surface 30 and the end of the interface S2 closer tothe medium facing surface 30. However, in the fourth embodiment, as inthe third embodiment, the distance between the medium facing surface 30and the end of the nonmagnetic layer 28B closer to the medium facingsurface 30 may be greater than the distance between the medium facingsurface 30 and the end of the interface S2 closer to the medium facingsurface 30 as shown in FIG. 14, or may be smaller than the distancebetween the medium facing surface 30 and the end of the interface S2closer to the medium facing surface 30 as shown in FIG. 15.

The remainder of configuration, function and effects of the fourthembodiment are similar to those of the third embodiment.

Fifth Embodiment

Reference is now made to FIG. 17 to describe a magnetic head of a fifthembodiment of the invention. FIG. 17 is a cross-sectional view forillustrating the configuration of the magnetic head of the fifthembodiment. FIG. 17 illustrates a cross section orthogonal to the mediumfacing surface and the plane of the substrate.

The magnetic head of the fifth embodiment is similar to the magnetichead of the third embodiment but has differences as will now bedescribed. In the fifth embodiment, the interface S1 has an area greaterthan that of the interface S2. When seen in the direction orthogonal tothe interface S2, the interface S2 is located to coincide with only partof the interface S1. In addition, the distance between the medium facingsurface 30 and the end of the interface S2 closer to the medium facingsurface 30 is greater than the distance between the medium facingsurface 30 and the end of the interface S1 closer to the medium facingsurface 30. The nonmagnetic layer 28B is located in a region greaterthan the interface S2 when seen in the direction orthogonal to theinterface S2. The nonmagnetic layer 28B is disposed at a location thatcoincides with the entire interface S2 when seen in the directionorthogonal to the interface S2 and that also coincides with the entireinterface S1 when seen in the direction orthogonal to the interface S1.In FIG. 17 the arrows in the first magnetic layer 9, the magnetic layer18 and the second magnetic layer 20 schematically show the directions inwhich magnetic fluxes flow.

In the fifth embodiment the area of the interface S2 may be greater thanthat of the interface S1, which is the opposite to the example of FIG.17. In the fifth embodiment, it suffices that at least part of theinterface S2, at least part of the interface S1, and at least part ofthe nonmagnetic layer 28B are disposed at locations that coincide withone another when seen in the direction orthogonal to the interface S2,as in the third embodiment. In the fifth embodiment, as in the fourthembodiment, the insulating layer 29 may be provided in place of thefirst layer 9A of the magnetic layer 9.

The remainder of configuration, function and effects of the fifthembodiment are similar to those of the third embodiment.

Sixth Embodiment

Reference is now made to FIG. 18 to describe a magnetic head of a sixthembodiment of the invention. FIG. 18 is a cross-sectional view forillustrating the configuration of the magnetic head of the sixthembodiment. FIG. 18 illustrates a cross section orthogonal to the mediumfacing surface and the plane of the substrate.

The magnetic head of the sixth embodiment is similar to the magnetichead of the second embodiment but has differences as will now bedescribed. In the magnetic head of the sixth embodiment, when seen inthe direction orthogonal to the interface S3 between the second layer 9Band the lower yoke layer 18C, at least part of the interface S3 isdisposed at a location that coincides with at least part of theinterface S4 between the third layer 20C and the pole layer 18A. Themagnetic head of the sixth embodiment has a nonmagnetic layer 28A madeof a nonmagnetic material and disposed between the pole layer 18A andthe lower yoke layer 18C. When seen in the direction orthogonal to theinterface S3, at least part of the nonmagnetic layer 28A is disposed ata location that coincides with at least part of the interface S3. Thelower yoke layer 18C is connected to the pole layer 18A at least at alocation closer to the medium facing surface 30 than the nonmagneticlayer 28A. The material and thickness of the nonmagnetic layer 28A maybe the same as those of the nonmagnetic layer 28B of the thirdembodiment.

In the embodiment, when seen in the direction orthogonal to theinterface S3, at least part of the interface S3, at least part of theinterface S4, and at least part of the nonmagnetic layer 28A aredisposed in regions that coincide with one another.

The distance between the medium facing surface 30 and an end of thenonmagnetic layer 28A farther from the medium facing surface 30 ispreferably equal to or greater than the distance between the mediumfacing surface 30 and an end of the interface S3 farther from the mediumfacing surface 30.

The method of manufacturing the magnetic head of the sixth embodimentincludes the step of forming the nonmagnetic layer 28A on the lower yokelayer 18C before forming the pole layer 18A.

In FIG. 18 the arrows in the magnetic layer 9, the magnetic layer 18 andthe magnetic layer 20 schematically show the directions in whichmagnetic fluxes flow. If the nonmagnetic layer 28A is not provided, amagnetic flux that has come into the lower yoke layer 18C from thesecond layer 9B and a magnetic flux that has come into the pole layer18A from the third layer 20C repel each other in the magnetic layer 18,and the flux density of the magnetic layer 18 may be reduced, which mayresult in degradation of overwrite property. In the sixth embodiment, incontrast, the nonmagnetic layer 28A is provided between the pole layer18A and the lower yoke layer 18C in a region where the interfaces S3 andS4 are opposed to each other. As a result, according to the embodiment,it is possible to suppress repulsion between the flux that has come intothe lower yoke layer 18C from the second layer 9B and the flux that hascome into the pole layer 18A from the third layer 20C in the magneticlayer 18. It is thereby possible to prevent a reduction in flux densityof the magnetic layer 18 and to thereby improve the overwrite property.

FIG. 18 illustrates an example in which the distance between the mediumfacing surface 30 and the end of the nonmagnetic layer 28A closer to themedium facing surface 30 is equal to the distance between the mediumfacing surface 30 and an end of the interface S3 closer to the mediumfacing surface 30. However, as in the third embodiment, the distancebetween the medium facing surface 30 and the end of the nonmagneticlayer 28A closer to the medium facing surface 30 may be greater than thedistance between the medium facing surface 30 and the end of theinterface S3 closer to the medium facing surface 30, or may be smallerthan the distance between the medium facing surface 30 and the end ofthe interface S3 closer to the medium facing surface 30.

In the sixth embodiment the insulating layer 29 may be provided in placeof the first layer 9A of the magnetic layer 9 as in the fourthembodiment. In the sixth embodiment the areas of the interfaces S1 andS2 may be different from each other as in the fifth embodiment.

The remainder of configuration, function and effects of the sixthembodiment are similar to those of the second embodiment.

Seventh Embodiment

Reference is now made to FIG. 19 to describe a magnetic head of aseventh embodiment of the invention and a method of manufacturing thesame. FIG. 19 is a cross-sectional view for illustrating theconfiguration of the magnetic head of the seventh embodiment. FIG. 19illustrates a cross section orthogonal to the medium facing surface andthe plane of the substrate.

The magnetic head of the seventh embodiment is similar to the magnetichead of the third embodiment but has differences as will now bedescribed. In the magnetic head of the seventh embodiment, a secondmagnetic layer 40 for flux concentration and a shield layer 50 areprovided in place of the second magnetic layer 20 for flux concentrationof the third embodiment.

The magnetic layer 40 for flux concentration is disposed forward of theupper yoke layer 18B of the magnetic layer 18 for writing along thedirection T of travel of the recording medium at a location away fromthe medium facing surface 30 and is connected to the upper yoke layer18B. The second coil 23 is wound around the magnetic layer 40. Themagnetic layer 40 allows a magnetic flux corresponding to the fieldgenerated by the second coil 23 to pass. The magnetic layer 40 has afunction of allowing a magnetic flux corresponding to the fieldgenerated by the coil 23 to concentrate in the magnetic layer 40.

The shield layer 50 incorporates a first layer 50A and a second layer50B. The first layer 50A is disposed on the gap layer 19. The firstlayer 50A has an end face located in the medium facing surface 30. Inthe medium facing surface 30 the end face of the first layer 50A islocated at a specific distance created by the thickness of the gap layer19 from the end face of the pole layer 18A. The first layer 50A mayincorporate: a middle portion including a portion opposed to the polelayer 18A with the gap layer 19 disposed in between; and two sideportions disposed outside the middle portion along the direction oftrack width. The maximum length of each of the side portions taken inthe direction orthogonal to the medium facing surface 30 is greater thanthe length of the middle portion taken in the direction orthogonal tothe medium facing surface 30.

The second layer 50B is disposed on the first layer 50A and connectedthereto. The second layer 50B has an end face located in the mediumfacing surface 30. In a cross section that passes the track widthdefining portion 18A1 of the pole layer 18A and is orthogonal to themedium facing surface 30 and the plane of the substrate 1, the length ofthe second layer 50B taken in the direction orthogonal to the mediumfacing surface 30 is greater than the length of the first layer 50Ataken in the direction orthogonal to the medium facing surface 30. Inthe seventh embodiment, as shown in FIG. 19, the throat height TH is thedistance from the medium facing surface 30 to the point at which thespace between the pole layer 18A and the shield layer 50 starts toincrease when seen from the medium facing surface 30.

The coil 23, the insulating layer 24, the magnetic layer 40 and thesecond layer 50B have flattened top surfaces. The protection layer 25 isdisposed on these flattened top surfaces. Therefore, the magnetic layer40 is not connected to the shield layer 50. The shield layer 50 takes ina disturbance magnetic field applied to the magnetic head from outsidethe magnetic head. As a result, it is possible to prevent erroneouswriting on the recording medium caused by the disturbance magnetic fieldintensively taken in into the pole layer 18A. Furthermore, the shieldlayer 50 has a function of taking in a magnetic flux generated from theend face of the pole layer 18A and extending in directions except thedirection orthogonal to the surface of the recording medium, andpreventing this flux from reaching the recording medium.

Each layer making up the magnetic layer 40 and the shield layer 50 ismade of a magnetic material. The material may be any of CoFeN, CoNiFe,NiFe and CoFe, for example.

When seen in a direction orthogonal to the interface between themagnetic layer 40 and the magnetic layer 18, that is, the interface S2between the magnetic layer 40 and the upper yoke layer 18B, (seen fromthe top or bottom of FIG. 19), the coil 23 is wound around the interfaceS2. When seen in a direction orthogonal to the interface S2, at leastpart of the interface S2 is disposed at a location that coincides withat least part of the interface S1 between the second layer 9B and thepole layer 18A.

As in the third embodiment, the magnetic head of the seventh embodimenthas the nonmagnetic layer 28B disposed between the pole layer 18A andthe upper yoke layer 18B. When seen in the direction orthogonal to theinterface S2, at least part of the nonmagnetic layer 28B is disposed ata location that coincides with at least part of the interface S2. Theupper yoke layer 18B is connected to the pole layer 18A at least at alocation closer to the medium facing surface 30 than the nonmagneticlayer 28B. When seen in the direction orthogonal to the interface S2, atleast part of the interface S2, at least part of the interface S1, andat least part of the nonmagnetic layer 28B are disposed at locationsthat coincide with one another.

The distance between the medium facing surface 30 and the end of thenonmagnetic layer 28B farther from the medium facing surface 30 ispreferably equal to or greater than the distance between the mediumfacing surface 30 and the end of the interface S2 farther from themedium facing surface 30.

As does FIG. 13, FIG. 19 shows an example in which the distance betweenthe medium facing surface 30 and the end of the nonmagnetic layer 28Bcloser to the medium facing surface 30 is equal to the distance betweenthe medium facing surface 30 and the end of the interface S2 closer tothe medium facing surface 30. However, in the seventh embodiment, as inthe third embodiment, the distance between the medium facing surface 30and the end of the nonmagnetic layer 28B closer to the medium facingsurface 30 may be greater than the distance between the medium facingsurface 30 and the end of the interface S2 closer to the medium facingsurface 30 as shown in FIG. 14, or may be smaller than the distancebetween the medium facing surface 30 and the end of the interface S2closer to the medium facing surface 30 as shown in FIG. 15.

The method of manufacturing the magnetic head of the seventh embodimentincludes the steps up to the step of forming the coil 23 and theinsulating layer 24 that are the same as those of the first embodiment.In the seventh embodiment, however, the first layer 50A of the shieldlayer 50 is formed in place of the first layer 20A of the magnetic layer20 for flux concentration of the first embodiment.

In the seventh embodiment, after the coil 23 and the insulating layer 24are formed, the second layer 50B are formed on the first layer 50A andthe nonmagnetic layer 21, and the second magnetic layer 40 is formed onthe upper yoke layer 18B. Next, a coating layer not shown made ofalumina, for example, is formed on the entire top surface of the layeredstructure. Next, the coating layer is polished by CMP, for example, sothat the coil 23, the second layer 50B and the magnetic layer 40 areexposed, and the top surfaces of the coil 23, the insulating layer 24,the second layer 50B, the magnetic layer 40 and the coating layer arethereby flattened. Next, the protection layer 25 is formed to cover theentire top surface of the layered structure. Wiring and terminals arethen formed on the protection layer 25, the substrate is cut intosliders, and the steps including polishing of the medium facing surface30 and fabrication of flying rails are performed. The magnetic head isthus completed.

Reference is now made to FIG. 20 to describe a reference magnetic head.FIG. 20 is a cross-sectional view for illustrating the configuration ofthe reference magnetic head. FIG. 20 illustrates a cross sectionorthogonal to the medium facing surface and the plane of the substrate.The configuration of the reference magnetic head is similar to that ofthe magnetic head of the seventh embodiment except that the referencemagnetic head does not have the nonmagnetic layer 28B. No magnetic layeris provided to connect the magnetic layer 40 and the shield layer 50 toeach other in either the reference magnetic head or the magnetic head ofthe embodiment. If a magnetic layer for connecting the magnetic layer 40and the shield layer 50 to each other is provided, this magnetic layeris likely to expand by receiving the heat generated by the coil 23, sothat the end face of the shield layer 50 located in the medium facingsurface 30 (the end face of the first layer 50A and the end face of thesecond layer 50B) is likely to protrude. In contrast, since no magneticlayer for connecting the magnetic layer 40 and the shield layer 50 toeach other is provided in either the reference magnetic head or themagnetic head of the embodiment, it is possible to suppress protrusionof the end face of the shield layer 50 resulting from the heat generatedby the coil 23.

In FIG. 19 and FIG. 20 the arrows in the first magnetic layer 9, themagnetic layer 18 and the second magnetic layer 40 schematically showthe directions in which magnetic fluxes flow. In the reference magnetichead, since the nonmagnetic layer 28B is not provided as shown in FIG.20, a magnetic flux that has come into the pole layer 18A from thesecond layer 9B and a magnetic flux that has come into the upper yokelayer 18B from the magnetic layer 40 repel each other in the magneticlayer 18, and the flux density of the magnetic layer 18 may be reduced,which may result in degradation of overwrite property. In the seventhembodiment, in contrast, the nonmagnetic layer 28B is provided betweenthe pole layer 18A and the upper yoke layer 18B in the region where theinterfaces S1 and S2 are opposed to each other, as shown in FIG. 19. Asa result, according to the embodiment, it is possible to suppressrepulsion between the flux that has come into the pole layer 18A fromthe second layer 9B and the flux that has come into the upper yoke layer18B from the magnetic layer 40 in the magnetic layer 18. It is therebypossible to prevent a reduction in flux density of the magnetic layer 18and to thereby improve the overwrite property.

The remainder of configuration, function and effects of the seventhembodiment are similar to those of the third embodiment.

Modification Example

FIG. 21 is a cross-sectional view for illustrating the configuration ofa magnetic head of a modification example of the seventh embodiment.FIG. 21 illustrates a cross section orthogonal to the medium facingsurface and the plane of the substrate. In the magnetic head of themodification example, the second magnetic layer 40 incorporates: a firstlayer 40A disposed forward of the upper yoke layer 18B along thedirection T of travel of the recording medium at a location away fromthe medium facing surface 30 and connected to the upper yoke layer 18B;and a second layer 40B disposed on the first layer 40A and connectedthereto. The shield layer 50 incorporates a third layer 50C in additionto the first layer 50A and the second layer 50B. The third layer 50C isdisposed on the second layer 50B and connected thereto. The third layer50C has an end face located closer to the medium facing surface 30 andthis end face is located at a distance from the medium facing surface30. It is not absolutely necessary to provide the third layer 50C,however.

In the magnetic head of the modification example, an insulating layer 51is provided in place of the insulating layer 22. The insulating layer 51is made of alumina, for example. The second layer 50B, the first layer40A and the insulating layer 51 have flattened top surfaces. The coil 23and the insulating layer 24 are disposed on the insulating layer 51. Thecoil 23 is wound around the second layer 40B. An insulating layer 52 isdisposed around the third layer 50C, the second layer 40B, the coil 23and the insulating layer 24. The insulating layer 52 is made of alumina,for example. The third layer 50C, the second layer 40B, the coil 23, andthe insulating layers 24 and 52 have flattened top surfaces. Theprotection layer 25 is disposed on the flattened top surfaces. Theremainder of configuration of the magnetic head of the modificationexample is the same as that of the magnetic head of FIG. 19.

FIG. 22 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the magnetic head of themodification example. FIG. 22 illustrates a cross section orthogonal tothe medium facing surface and the plane of the substrate. Theconfiguration of the reference magnetic head is similar to that of themagnetic head of the modification example shown in FIG. 21 except thatthe nonmagnetic layer 28B is not provided. The second magnetic layer 40incorporates the first layer 40A and the second layer 40B in each of thereference magnetic head shown in FIG. 22 and the magnetic head of themodification example shown in FIG. 21. Therefore, these magnetic headsare capable of allowing magnetic fluxes of greater amount to concentratein the magnetic layer 40.

In FIG. 21 and FIG. 22 the arrows in the first magnetic layer 9, themagnetic layer 18 and the second magnetic layer 40 schematically showthe directions in which magnetic fluxes flow. In the reference magnetichead, since the nonmagnetic layer 28B is not provided as shown in FIG.22, the flux density of the magnetic layer 18 may be reduced, which mayresult in degradation of overwrite property, as previously described. Inthe magnetic head of the modification example, in contrast, thenonmagnetic layer 28B is provided between the pole layer 18A and theupper yoke layer 18B in the region where the interfaces S1 and S2 areopposed to each other, as shown in FIG. 21. As a result, according tothe magnetic head of the modification example, it is possible to preventa reduction in flux density of the magnetic layer 18 and to therebyimprove the overwrite property, as previously described.

Eighth Embodiment

Reference is now made to FIG. 23 to FIG. 25 to describe a magnetic headof an eighth embodiment of the invention. FIG. 23 is a cross-sectionalview for illustrating the configuration of the magnetic head of theeighth embodiment. FIG. 23 illustrates a cross section orthogonal to themedium facing surface and the plane of the substrate. FIG. 24 is a frontview illustrating the medium facing surface of the magnetic head of theembodiment. FIG. 25 is a cross-sectional view taken along line 25-25 ofFIG. 23.

The magnetic head of the eighth embodiment is similar to the magnetichead of the seventh embodiment but has differences as will now bedescribed. In the eighth embodiment, the end face of the first layer 9Aof the first magnetic layer 9 closer to the medium facing surface 30 islocated at a distance from the medium facing surface 30. An insulatinglayer 32 is disposed around the first layer 9A. The insulating layer 32is made of alumina, for example. The first layer 9A and the insulatinglayer 32 have flattened top surfaces.

The magnetic head of the eighth embodiment has a coupling portion 60that connects the first layer 50A of the shield layer 50 to the firstlayer 9A of the first magnetic layer 9 without touching the magneticlayer 18. As shown in FIG. 25, the coupling portion 60 incorporates: amagnetic layer 63 disposed on a region of the first layer 9A between thecoil 11 and the medium facing surface 30; and two magnetic layers 61 and62 disposed on the magnetic layer 63.

The magnetic layer 63, the second layer 9B, the coil 11, and theinsulating layers 12 and 13 have flattened top surfaces. The magneticlayers 61 and 62 are disposed on both sides of the pole layer 18A, thesides being opposed to each other in the direction of track width, andcouple the first layer 50A to the magnetic layer 63. Each of themagnetic layers 61 to 63 is made of a magnetic material. The materialmay be any of CoFeN, CoNiFe, NiFe and CoFe, for example.

In the eighth embodiment, the first layer 50A incorporates: a middleportion including a portion opposed to the pole layer 18A with the gaplayer 19 disposed in between; and two side portions located outside themiddle portion along the direction of track width. The maximum length ofeach of the side portions taken in the direction orthogonal to themedium facing surface 30 is greater than the length of the middleportion taken in the direction orthogonal to the medium facing surface30. The magnetic layers 61 and 62 are respectively connected to the twoside portions of the first layer 50A.

In the method of manufacturing the magnetic head of the eighthembodiment, the magnetic layer 63 is formed at the same time as thesecond layer 9B. In the eighth embodiment the magnetic layers 61 and 62are formed on the magnetic layer 63 before the nonmagnetic layer 14P tobe the encasing layer 14 is formed. The nonmagnetic layer 14P is thenformed. Next, the nonmagnetic layer 14P is polished by CMP, for example,so that the magnetic layers 61 and 62 are exposed, and the top surfacesof the magnetic layers 61 and 62 and the nonmagnetic layer 14P arethereby flattened. In the eighth embodiment, after the gap layer 19 isformed, portions of the gap layer 19, the polishing stopper layer 17,the nonmagnetic film 16 and the nonmagnetic metal layer 15 that arelocated on the magnetic layers 61 and 62 are selectively etched toexpose the top surfaces of the magnetic layers 61 and 62. The firstlayer 50A is then formed on the gap layer 19 and the magnetic layers 61and 62.

In the magnetic head of the eighth embodiment, the first layer 50A ofthe shield layer 50 is coupled to the first layer 9A of the firstmagnetic layer 9 for flux concentration by the coupling portion 60. As aresult, according to the embodiment, a magnetic flux taken in from theend face of the shield layer 50 located in the medium facing surface 30passes through the coupling portion 60 and the first magnetic layer 9and flows into the pole layer 18A. As a result, according to theembodiment, the shield layer 50 also has a function of returning theflux that has been generated from the end face of the pole layer 18A andhas magnetized the recording medium.

According to the embodiment, it is possible to take in magnetic fluxesof great amount from the end face of the shield layer 50. As a result,according to the embodiment, it is possible to precisely define thelocation of the end of a bit pattern to be written on the recordingmedium. According to the embodiment, an improvement in linear recordingdensity is thereby achieved.

FIG. 26 is a cross-sectional view for illustrating the configuration ofa reference magnetic head. FIG. 26 illustrates a cross sectionorthogonal to the medium facing surface and the plane of the substrate.The configuration of the reference magnetic head is similar to that ofthe magnetic head of FIG. 23 except that the nonmagnetic layer 28B isnot provided. The reference magnetic head of FIG. 26 has theabove-described effects, too.

In FIG. 23 and FIG. 26 the arrows in the first magnetic layer 9, themagnetic layer 18 and the second magnetic layer 40 schematically showthe directions in which magnetic fluxes flow. In the reference magnetichead, since the nonmagnetic layer 28B is not provided as shown in FIG.26, the flux density of the magnetic layer 18 may be reduced, which mayresult in degradation of overwrite property, as described in the seventhembodiment. In the magnetic head of the embodiment, in contrast, thenonmagnetic layer 28B is provided between the pole layer 18A and theupper yoke layer 18B in the region where the interfaces S1 and S2 areopposed to each other, as shown in FIG. 23. As a result, according tothe magnetic head of the embodiment, it is possible to prevent areduction in flux density of the magnetic layer 18 and to therebyimprove the overwrite property, as in the seventh embodiment.

The remainder of configuration, function and effects of the eighthembodiment are similar to those of the seventh embodiment.

Modification Example

FIG. 27 is a cross-sectional view for illustrating the configuration ofa magnetic head of a modification example of the eighth embodiment. FIG.27 illustrates a cross section orthogonal to the medium facing surfaceand the plane of the substrate. In the magnetic head of the modificationexample, as in the modification example of the seventh embodiment, thesecond magnetic layer 40 incorporates the first layer 40A and the secondlayer 40B, and the shield layer 50 incorporates the third layer 50C inaddition to the first layer 50A and the second layer 50B. It is notabsolutely necessary to provide the third layer 50C, however.

In the magnetic head of this modification example, as in themodification example of the seventh embodiment, the insulating layer 51is provided in place of the insulating layer 22, and the top surfaces ofthe second layer 50B, the first layer 40A and the insulating layer 51are flattened. The coil 23 and the insulating layer 24 are disposed onthe insulating layer 51. The coil 23 is wound around the second layer40B. The insulating layer 52 is disposed around the third layer 50C, thesecond layer 40B, the coil 23 and the insulating layer 24. The topsurfaces of the third layer 50C, the second layer 40B, the coil 23, andthe insulating layers 24 and 52 are flattened. The protection layer 25is disposed on the flattened top surfaces. The remainder ofconfiguration of the magnetic head of the modification example is thesame as that of the magnetic head of FIG. 23.

FIG. 28 is a cross-sectional view for illustrating the configuration ofa reference magnetic head compared with the magnetic head of themodification example. FIG. 28 illustrates a cross section orthogonal tothe medium facing surface and the plane of the substrate. Theconfiguration of the reference magnetic head is similar to that of themagnetic head of the modification example shown in FIG. 27 except thatthe nonmagnetic layer 28B is not provided. The second magnetic layer 40incorporates the first layer 40A and the second layer 40B in each of thereference magnetic head shown in FIG. 28 and the magnetic head of themodification example shown in FIG. 27. Therefore, these magnetic headsare capable of allowing magnetic fluxes of greater amount to concentratein the magnetic layer 40.

In FIG. 27 and FIG. 28 the arrows in the first magnetic layer 9, themagnetic layer 18 and the second magnetic layer 40 schematically showthe directions in which magnetic fluxes flow. In the reference magnetichead, since the nonmagnetic layer 28B is not provided as shown in FIG.28, the flux density of the magnetic layer 18 may be reduced, which mayresult degradation of overwrite property, as previously described. Inthe magnetic head of the modification example, in contrast, thenonmagnetic layer 28B is provided between the pole layer 18A and theupper yoke layer 18B in the region where the interfaces S1 and S2 areopposed to each other, as shown in FIG. 27. As a result, according tothe magnetic head of the modification example, it is possible to preventa reduction in flux density of the magnetic layer 18 and to therebyimprove the overwrite property, as previously described.

Ninth Embodiment

Reference is now made to FIG. 29 to describe a magnetic head of a ninthembodiment of the invention. FIG. 29 is a cross-sectional view forillustrating the configuration of the magnetic head of the ninthembodiment. FIG. 29 illustrates a cross section orthogonal to the mediumfacing surface and the plane of the substrate.

The magnetic head of the ninth embodiment is similar to the magnetichead of the seventh embodiment but has differences as will now bedescribed. In the magnetic head of the ninth embodiment, the insulatinglayer 13 is provided to cover the first coil 11 and the insulating layer12. The top surfaces of the insulating layer 13 and the second layer 9Bare flattened.

In the ninth embodiment the lower yoke layer 18C is provided in place ofthe upper yoke layer 18B of the seventh embodiment. The magnetic layer18 for writing of the ninth embodiment incorporates the pole layer 18Aand the lower yoke layer 18C. The lower yoke layer 18C is connected tothe pole layer 18A and disposed backward of the pole layer 18A along thedirection T of travel of the recording medium at a location away fromthe medium facing surface 30. The lower yoke layer 18C is disposed onthe insulating layer 13 and the second layer 9B.

In the ninth embodiment the second magnetic layer 40 for fluxconcentration incorporates: the first layer 40A connected to the polelayer 18A and disposed forward of the pole layer 18A along the directionT of travel of the recording medium at a location away from the mediumfacing surface 30; and the second layer 40B disposed on the first layer40A and connected thereto.

In the ninth embodiment an insulating layer 53 is provided in place ofthe nonmagnetic layer 21 of the seventh embodiment. The insulating layer53 is disposed around the first layer 50A and the first layer 40A. Theinsulating layer 53 is made of alumina, for example. The first layer50A, the first layer 40A and the insulating layer 53 have flattened topsurfaces. In the ninth embodiment the second coil 23 and the insulatinglayer 24 are disposed on the insulating layer 53.

In the ninth embodiment the second layer 9B of the first magnetic layer9 is connected to the lower yoke layer 18C, and the first layer 40A ofthe second magnetic layer 40 is connected to the pole layer 18A. Thelower yoke layer 18C is made of a magnetic material. The material may beany of CoFeN, CoNiFe, NiFe and CoFe, for example.

In the ninth embodiment the interface between the first magnetic layer 9and the magnetic layer 18 is the interface S3 between the second layer9B and the lower yoke layer 18C. When seen in the direction orthogonalto the interface S3, the coil 11 is wound around the interface S3.Furthermore, the interface between the second magnetic layer 40 and themagnetic layer 18 is the interface S4 between the first layer 40A andthe pole layer 18A. When seen in the direction orthogonal to theinterface S4, the coil 23 is wound around the interface S4. When seen inthe direction orthogonal to the interface S3, at least part of theinterface S3 is disposed at a location that coincides with at least partof the interface S4.

The magnetic head of the ninth embodiment has the nonmagnetic layer 28Amade of a nonmagnetic material and disposed between the pole layer 18Aand the lower yoke layer 18C. When seen in the direction orthogonal tothe interface S3, at least part of the nonmagnetic layer 28A is disposedat a location that coincides with at least part of the interface S3. Thelower yoke layer 18C is connected to the pole layer 18A at least at alocation closer to the medium facing surface 30 than the nonmagneticlayer 28A. The material and thickness of the nonmagnetic layer 28A arethe same as those of the sixth embodiment.

In the ninth embodiment, when seen in the direction orthogonal to theinterface S3, at least part of the interface S3, at least part of theinterface S4, and at least part of the nonmagnetic layer 28A aredisposed at locations that coincide with one another.

The distance between the medium facing surface 30 and the end of thenonmagnetic layer 28A farther from the medium facing surface 30 ispreferably equal to or greater than the distance between the mediumfacing surface 30 and the end of the interface S3 farther from themedium facing surface 30.

FIG. 30 is a cross-sectional view for illustrating the configuration ofa reference magnetic head. FIG. 30 illustrates a cross sectionorthogonal to the medium facing surface and the plane of the substrate.The configuration of the reference magnetic head is similar to that ofthe magnetic head of the ninth embodiment except that the nonmagneticlayer 28A is not provided.

In FIG. 29 and FIG. 30 the arrows in the first magnetic layer 9, themagnetic layer 18 and the second magnetic layer 40 schematically showthe directions in which magnetic fluxes flow. In the reference magnetichead, since the nonmagnetic layer 28A is not provided as shown in FIG.30, a magnetic flux that has come into the lower yoke layer 18C from thesecond layer 9B and a magnetic flux that has come into the pole layer18A from the first layer 40A repel each other, and the flux density ofthe magnetic layer 18 may be thereby reduced, which may result indegradation of overwrite property. In the ninth embodiment, in contrast,the nonmagnetic layer 28A is provided between the pole layer 18A and thelower yoke layer 18C in the region where the interfaces S3 and S4 areopposed to each other, as shown in FIG. 29. As a result, according tothe embodiment, it is possible to suppress repulsion between the fluxthat has come into the lower yoke layer 18C from the second layer 9B andthe flux that has come into the pole layer 18A from the first layer 40Ain the magnetic layer 18. It is thereby possible to prevent a reductionin flux density of the magnetic layer 18 and to thereby improve theoverwrite property.

The remainder of configuration, function and effects of the ninthembodiment are similar to those of the seventh embodiment.

Tenth Embodiment

Reference is now made to FIG. 31 to describe a magnetic head of a tenthembodiment of the invention. FIG. 31 is a cross-sectional view forillustrating the configuration of the magnetic head of the tenthembodiment. FIG. 31 illustrates a cross section orthogonal to the mediumfacing surface and the plane of the substrate.

The magnetic head of the tenth embodiment is similar to the magnetichead of the ninth embodiment but has differences as will now bedescribed. In the tenth embodiment, the end face of the first layer 9Aof the first magnetic layer 9 closer to the medium facing surface 30 islocated at a distance from the medium facing surface 30. The insulatinglayer 32 is disposed around the first layer 9A. The insulating layer 32is made of alumina, for example. The top surfaces of the first layer 9Aand the insulating layer 32 are flattened.

The magnetic head of the tenth embodiment has the coupling portion 60that connects the first layer 50A of the shield layer 50 to the firstlayer 9A of the first magnetic layer 9 without touching the magneticlayer 18. The configuration of the coupling portion 60 is the same asthat of the eighth embodiment.

In the magnetic head of the tenth embodiment, the first layer 50A of theshield layer 50 is coupled to the first layer 9A of the first magneticlayer 9 for flux concentration by the coupling portion 60. As a result,according to the embodiment, a magnetic flux taken in from the end faceof the shield layer 50 located in the medium facing surface 30 passesthrough the coupling portion 60, the first magnetic layer 9 and thelower yoke layer 18C and flows into the pole layer 18A. As a result,according to the embodiment, the shield layer 50 also has a function ofreturning the flux that has been generated from the end face of the polelayer 18A and has magnetized the recording medium.

According to the embodiment, it is possible to take in magnetic fluxesof great amount from the end face of the shield layer 50. As a result,according to the embodiment, it is possible to precisely define thelocation of the end of a bit pattern to be written on the recordingmedium. According to the embodiment, an improvement in linear recordingdensity is thereby achieved.

FIG. 32 is a cross-sectional view for illustrating the configuration ofa reference magnetic head. FIG. 32 illustrates a cross sectionorthogonal to the medium facing surface and the plane of the substrate.The configuration of the reference magnetic head is similar to that ofthe magnetic head of FIG. 31 except that the nonmagnetic layer 28A isnot provided. The reference magnetic head of FIG. 32 has theabove-described effects, too.

In FIG. 31 and FIG. 32 the arrows in the first magnetic layer 9, themagnetic layer 18 and the second magnetic layer 40 schematically showthe directions in which magnetic fluxes flow. In the reference magnetichead, since the nonmagnetic layer 28A is not provided as shown in FIG.32, the flux density of the magnetic layer 18 may be reduced, which mayresult in degradation of overwrite property, as described in the ninthembodiment. In the magnetic head of the tenth embodiment, in contrast,the nonmagnetic layer 28A is provided between the pole layer 18A and thelower yoke layer 18C in the region where the interfaces S1 and S2 areopposed to each other, as shown in FIG. 31. As a result, according tothe magnetic head of the embodiment, it is possible to prevent areduction in flux density of the magnetic layer 18 and to therebyimprove the overwrite property, as in the ninth embodiment.

The remainder of configuration, function and effects of the tenthembodiment are similar to those of the ninth embodiment.

Eleventh Embodiment

Reference is now made to FIG. 33 to describe a magnetic head of aneleventh embodiment of the invention. FIG. 33 is a cross-sectional viewfor illustrating the configuration of the magnetic head of the eleventhembodiment. FIG. 33 illustrates a cross section orthogonal to the mediumfacing surface and the plane of the substrate.

The magnetic head of the eleventh embodiment is similar to the magnetichead of the seventh embodiment but has differences as will now bedescribed. In the eleventh embodiment, the nonmagnetic layer 28B of theseventh embodiment is not provided. In the eleventh embodiment, whenseen in the direction orthogonal to the interface S2 between themagnetic layer 40 and the upper yoke layer 18B, the interface S2 isdisposed at a location that is closer to the medium facing surface 30than the interface S1 between the second layer 9B and the pole layer 18Aand that does not coincide with the interface S1. According to theembodiment, through the function the same as that of the firstembodiment, in the magnetic layer 18 it is possible to suppressrepulsion between the flux that has come into the pole layer 18A fromthe second layer 9B and the flux that has come into the upper yoke layer18B from the magnetic layer 40. It is thereby possible to prevent areduction in flux density of the magnetic layer 18 and to therebyimprove the overwrite property.

In the eleventh embodiment the interface S2 may be disposed at alocation that is farther from the medium facing surface 30 than theinterface S1 and that does not coincide with the interface S1. Theremainder of configuration, function and effects of the eleventhembodiment are similar to those of the seventh embodiment.

Twelfth Embodiment

Reference is now made to FIG. 34 to describe a magnetic head of atwelfth embodiment of the invention. FIG. 34 is a cross-sectional viewfor illustrating the configuration of the magnetic head of the twelfthembodiment. FIG. 34 illustrates a cross section orthogonal to the mediumfacing surface and the plane of the substrate.

The magnetic head of the twelfth embodiment is similar to the magnetichead of the eighth embodiment but has differences as will now bedescribed. In the twelfth embodiment, the nonmagnetic layer 28B of theeighth embodiment is not provided. In the twelfth embodiment, when seenin the direction orthogonal to the interface S2 between the magneticlayer 40 and the upper yoke layer 18B, the interface S2 is disposed at alocation that is closer to the medium facing surface 30 than theinterface S1 between the second layer 9B and the pole layer 18A and thatdoes not coincide with the interface S1. According to the embodiment,through the function the same as that of the first embodiment, in themagnetic layer 18 it is possible to suppress repulsion between the fluxthat has come into the pole layer 18A from the second layer 9B and theflux that has come into the upper yoke layer 18B from the magnetic layer40. It is thereby possible to prevent a reduction in flux density of themagnetic layer 18 and to thereby improve the overwrite property.

In the twelfth embodiment the interface S2 may be disposed at a locationthat is farther from the medium facing surface 30 than the interface S1and that does not coincide with the interface S1. The remainder ofconfiguration, function and effects of the twelfth embodiment aresimilar to those of the eighth embodiment.

Thirteenth Embodiment

Reference is now made to FIG. 35 to describe a magnetic head of athirteenth embodiment of the invention. FIG. 35 is a cross-sectionalview for illustrating the configuration of the magnetic head of thethirteenth embodiment. FIG. 35 illustrates a cross section orthogonal tothe medium facing surface and the plane of the substrate.

The magnetic head of the thirteenth embodiment is similar to themagnetic head of the ninth embodiment but has differences as will now bedescribed. In the thirteenth embodiment, the nonmagnetic layer 28A ofthe ninth embodiment is not provided. In the thirteenth embodiment, whenseen in the direction orthogonal to the interface S4 between the firstlayer 40A and the pole layer 18A, the interface S4 is disposed at alocation that is closer to the medium facing surface 30 than theinterface S3 between the second layer 9B and the lower yoke layer 18Cand that does not coincide with the interface S3. According to theembodiment, through the function the same as that of the secondembodiment, in the magnetic layer 18 it is possible to suppressrepulsion between the flux that has come into the lower yoke layer 18Cfrom the second layer 9B and the flux that has come into the pole layer18A from the first layer 40A. It is thereby possible to prevent areduction in flux density of the magnetic layer 18 and to therebyimprove the overwrite property.

In the thirteenth embodiment the interface S4 may be disposed at alocation that is farther from the medium facing surface 30 than theinterface S3 and that does not coincide with the interface S3. Theremainder of configuration, function and effects of the thirteenthembodiment are similar to those of the ninth embodiment.

Fourteenth Embodiment

Reference is now made to FIG. 36 to describe a magnetic head of afourteenth embodiment of the invention. FIG. 36 is a cross-sectionalview for illustrating the configuration of the magnetic head of thefourteenth embodiment. FIG. 36 illustrates a cross section orthogonal tothe medium facing surface and the plane of the substrate.

The magnetic head of the fourteenth embodiment is similar to themagnetic head of the tenth embodiment but has differences as will now bedescribed. In the fourteenth embodiment, the nonmagnetic layer 28A ofthe tenth embodiment is not provided. In the fourteenth embodiment, whenseen in the direction orthogonal to the interface S4 between the firstlayer 40A and the pole layer 18A, the interface S4 is disposed at alocation that is closer to the medium facing surface 30 than theinterface S3 between the second layer 9B and the lower yoke layer 18Cand that does not coincide with the interface S3. According to theembodiment, through the function the same as that of the secondembodiment, in the magnetic layer 18 it is possible to suppressrepulsion between the flux that has come into the lower yoke layer 18Cfrom the second layer 9B and the flux that has come into the pole layer18A from the first layer 40A. It is thereby possible to prevent areduction in flux density of the magnetic layer 18 and to therebyimprove the overwrite property.

In the fourteenth embodiment the interface S4 may be disposed at alocation that is farther from the medium facing surface 30 than theinterface S3 and that does not coincide with the interface S3. Theremainder of configuration, function and effects of the fourteenthembodiment are similar to those of the tenth embodiment.

The present invention is not limited to the foregoing embodiments butmay be practiced in still other ways. For example, in any of the eighth,tenth, twelfth and fourteenth embodiments, the pole layer 18A may have apenetrating hole, and the coupling portion 60 may pass through this holewithout touching the pole layer 18A and couple the first layer 50A ofthe shield layer 50 to the first layer 9A of the first magnetic layer 9for flux concentration.

The pole layer of the invention is not limited to the one formed in themanner disclosed in each of the embodiments but may be formed otherwise.For example, the pole layer may be formed by patterning a magnetic layerby etching, or may be formed by frame plating. The pole layer may have aflat top surface.

While the magnetic head disclosed in each of the embodiments has such aconfiguration that the read head is formed on the base body and thewrite head is stacked on the read head, it is also possible that theread head is stacked on the write head.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

1. A magnetic head for perpendicular magnetic recording comprising: amedium facing surface that faces toward a recording medium; a first coiland a second coil each generating a magnetic field corresponding to datato be written on the recording medium; a magnetic layer for writinghaving an end face located in the medium facing surface, allowing amagnetic flux corresponding to the field generated by each of the firstand second coils to pass therethrough, and generating a write magneticfield for writing the data on the recording medium by means of aperpendicular magnetic recording system; a first magnetic layer for fluxconcentration disposed backward of the magnetic layer for writing alonga direction of travel of the recording medium, connected to the magneticlayer for writing at a location away from the medium facing surface, andallowing a magnetic flux corresponding to the field generated by thefirst coil to pass; and a second magnetic layer for flux concentrationdisposed forward of the magnetic layer for writing along the directionof travel of the recording medium, connected to the magnetic layer forwriting at a location away from the medium facing surface, and allowinga magnetic flux corresponding to the field generated by the second coilto pass, wherein: the magnetic layer for writing incorporates: a polelayer having the end face located in the medium facing surface; and ayoke layer connected to the pole layer and disposed forward of the polelayer along the direction of travel of the recording medium at alocation away from the medium facing surface; the first magnetic layerfor flux concentration is connected to the pole layer; the secondmagnetic layer for flux concentration is connected to the yoke layer;when seen in a direction orthogonal to an interface between the firstmagnetic layer for flux concentration and the pole layer, the first coilis wound around the interface between the first magnetic layer for fluxconcentration and the pole layer; and when seen in a directionorthogonal to an interface between the second magnetic layer for fluxconcentration and the yoke layer, the second coil is wound around theinterface between the second magnetic layer for flux concentration andthe yoke layer, the magnetic head further comprising a nonmagnetic layermade of a nonmagnetic material and disposed between the pole layer andthe yoke layer, wherein: when seen in the direction orthogonal to theinterface between the second magnetic layer for flux concentration andthe yoke layer, at least part of the nonmagnetic layer is disposed at alocation that coincides with at least part of this interface; and theyoke layer is connected to the pole layer at least at a location closerto the medium facing surface than the nonmagnetic layer.
 2. The magnetichead according to claim 1, wherein: the second magnetic layer for fluxconcentration has an end face located in the medium facing surface; andpart of the second coil is disposed between the second magnetic layerfor flux concentration and the magnetic layer for writing.
 3. Themagnetic head according to claim 1, wherein the first magnetic layer forflux concentration has a portion located to sandwich part of the firstcoil between the magnetic layer for writing and itself.
 4. The magnetichead according to claim 1, further comprising: a shield layer disposedforward of the pole layer along the direction of travel of the recordingmedium and having an end face located in the medium facing surface; anda gap layer made of a nonmagnetic material and disposed between the polelayer and the shield layer, wherein: in the medium facing surface, theend face of the shield layer is located forward of the end face of thepole layer along the direction of travel of the recording medium with aspecific space created by a thickness of the gap layer; and the end faceof the pole layer has a side located adjacent to the gap layer, the sidedefining the track width.
 5. The magnetic head according to claim 4,wherein the first magnetic layer for flux concentration incorporates aportion located to sandwich part of the first coil between the magneticlayer for writing and itself, the magnetic head further comprising acoupling portion coupling the shield layer and the first magnetic layerfor flux concentration to each other without touching the magnetic layerfor writing.